Ideal Body Weight Formula

When I first meet a training, or coaching client, I normally ask, “How much would you like to change your weight?” Most of them pause, shrug their shoulders, and then reply, “I’m not sure, maybe…” then take a guess at how much weight they want to lose.

The amount of weight you want to lose (or gain) doesn’t have to be a guessing game. There’s a formula to calculate your goal weight more precisely so you can have that magic number in your head that motivates you to eat well and train hard.

Old Ideal Body Weight Formula: BMI

The most common method of measuring your ideal weight is using the Body Mass Index (BMI), which measures the relationship between your weight and your height.

Do you notice anything wrong with the traditional BMI calculation, which is used in almost every weight loss study? It doesn’t take into account your body fat percentage! In fact, Ancel Keys is given credit for popularizing BMI in a 1972 paper, but he explicitly stated BMI was appropriate for population studies, NOT individual diagnoses.

Using BMI, just about every NFL football player is considered obese, even though most have very low body fat percentages. Conversely, the number of “overfat” Americans is believed to be higher than what BMI predicts. You don’t have to be overweight by the BMI Index to be considered “overfat” on a body fat basis. Ideal Body Weight Formula

It turns out there’s a MUCH better way to calculate your ideal weight that takes into account your body fat percentage. Here it is:

Lean Body Mass/(1 – Desired Body Fat Percentage)

where Lean Body Mass (LBM) = Your Body Weight – (Your Body Weight x Your Current Body Fat Percentage)

Just to be clear, your LBM is your “fat free” mass, in other words, everything in your body that’s not fat: your bones, blood, muscle, and organs.

Let me give you an example of this ideal body weight formula in action so you can see why it’s so useful. Let’s take Jake who is 200 pounds and has 22% body fat. Using this information, we know that his LBM is 156 pounds and the amount of body fat he has is 44 pounds. So what should Jake’s ideal weight be? Well that’s really up to him. For most men, a mid double digit body fat percentage of say 15% is considered pretty good. Here’s a chart for your reference:

Ideal Body Weight Formula 2

So now, here’s the important part. We are going to assume Jake doesn’t lose any muscle because he has been following all the tips I’ve discussed so far on So keeping his LBM at 156 pounds, Jake needs to drop 16 pounds of fat to reach his desired body fat percentage of 15%. His ideal weight is 184 pounds in this scenario. Here’s how Jake’s ideal body weight calculation looks:

156/(1 – 0.15) = 184 pounds

See how valuable this is now? Your body weight doesn’t have to be a guessing game anymore. I’ll be following up with some articles on the various ways to calculate your body fat percentage. For now, I advise going to your local gym and having one of the trainers do a skin fold body fat measurement, or you can grab an Accu-Measure Personal Body Fat Caliper for $6 at and do it yourself (it’s surprisingly accurate for most people).

I hope this has cleared up some confusion for you and highlighted the importance of thinking about your weight in terms of your body fat percentage.



  1. profile avatar
    Alicia May 05, 2010 - 20:03 #

    Although my body fat percentage is good, I don’t think I have enough muscle. Is there a guideline/equation for how much one’s muscle mass should be for a specific height, age, and gender?

    1. profile avatar
      Marc Perry May 05, 2010 - 21:09 #

      That’s a good question. The guidelines I know about in terms of height/weight is the BMI, then in terms of body fat percentage is the ACE guidelines. I will write more about how to calculate body fat percentages, “ideal” body measurements, and various body fat percentages and what they mean. It’s tough to include everything in one post. Eventually, once I have written enough blog posts, I will link them together so will become a web of knowledge and a great free resource with depth and breadth.

  2. profile avatar
    Hank May 06, 2010 - 20:52 #

    When I look to calculate BMI I see that metric and English are reversed. It does not seem to matter though as I used pounds and inches on the metric scale and received a reasonable result. Unfortunately, I think that the scale does not really reflect people who are training. Using the Ideal formula seems more accurate but leaves me needing to knockoff 10 lbs of fat.

    1. profile avatar
      Marc Perry May 06, 2010 - 21:35 #

      Hi Hank, That’s strange, I don’t have that issue when I use the BMI calculator. I’ll try to see if I can resolve the issue, but if I can’t, then just take your weight in kg and divide it by the square of your height in meters. Using imperial units, take 703 and multiply it by your weight in pounds, then divide by the square of your height in inches.

  3. profile avatar
    Mary May 07, 2010 - 09:16 #

    I have never seen this information anywhere. It is so interesting to be able to actually calculate body fat. This is so helpful.

  4. profile avatar
    Lost Lettermen May 10, 2010 - 11:25 #

    Great Article!!

    1. profile avatar
      Marc Perry May 10, 2010 - 14:05 #

      Thanks a lot. I appreciate it!

  5. profile avatar
    Ketch Rudder May 10, 2010 - 22:39 #

    There’s a theoretical weight maximum that any musculoskeletal system can support without surpassing health-risking, excessive body fat.

    The only way for someone to exceed the weight maximum is to pack on adipose tissue (body fat).

    To calculate your weight maximum, starting from a baseline, which differs for males and for females, add or subtract weight.

    For men, the baseline is 5-feet, 9-inches tall and a Maximum Weight Limit of 175 pounds. Add or subtract 5 pounds for every inch you are taller or shorter than 5 feet, 9 inches

    For women, the baseline is 5-feet tall and a Maximum Weight Limit of 125 pounds. Add or subtract 4.5 pounds for each inch you are taller or shorter than 5 feet.

    Your Lean Body Mass (LBM) formula amounts to overly complicated foolery.

    Clearly, a man who works out regularly and stands 5’9″, 175 is going to be healthier than a man who stands the same height and weight but never works out. The same can be said for the 5′ woman weight is 125.

    1. profile avatar
      Marc Perry May 11, 2010 - 07:55 #

      I see where you’re coming from. There is one more layer that I did not touch upon that relates to dividing LBM by someone’s height. So the way to arrive at the theoretical weight maximum you are referring to, is to use LBM vs. weight, come up with some type of maximum ratio, then take the highest body fat percentage acceptable (whatever that is). That’s the theoretical weight maximum. There should also be a theoretical minimum as well. I’m going to explore this in more depth in another post. I didn’t want to make this current post too long.

      The LBM formula is definitely not appropriate for population studies, but I find it EXTREMELY valuable with individual clients and use it all the time. Separating LBM from fat and playing with different desired body fat percentages and how that relates to body weight is very, very useful. Also, I love how the formula allows for changes in LBM assumptions if someone gains/loses muscle to arrive at their new weight.

  6. profile avatar
    Fat Loss Guy Sep 16, 2010 - 15:57 #

    Some good points here. Will add this to my rss reader.

    1. profile avatar
      Marc Perry Sep 19, 2010 - 22:32 #

      @ Fat Loss Guy – Thanks a lot for the kind words. I just realized the RSS reader is not working for some reason, so I’ll make sure that I can get that fixed up and let you know!

  7. profile avatar
    sonic produce Oct 18, 2010 - 15:08 #

    How did you manage to make a blog thats as smart as it is sleek? I mean, its like an Aston Martin –smart and sexy at the same time.

  8. profile avatar
    palletdozen Mar 15, 2011 - 06:23 #

    I really enjoy when people are indicating their judgment and idea. And so I prefer the way you are producing.

  9. profile avatar
    Connie May 14, 2011 - 17:22 #

    But how does your skeletal makeup reflect in all this? It seems Ketch Rudder’s baseline post seems overly simplistic, especially for the skeletal makeup. I’m no expert, just an ordinary person with a question and thought. I’m 5′ 1″ and female. Some women at my height have sparrow like bone structure, whereas, I have a much thicker bone structure. The sparrow can look perfectly fine at 100 lbs or even less. I look and feel awful at less than about 115 and actually feel healthiest at around 125. Wouldn’t the max weight on a sparrow skeleton be less than a heavier skeleton?

    1. profile avatar
      Marc Perry May 18, 2011 - 12:50 #

      @Connie – Thanks for the comment. I’m not familiar with “Ketch Rudder”, but I do understand your valid point that different people have different bone structures and therefore LBM’s. As you say, someone who has a thinner bone structure should weigh less than someone at the same height with a thicker bone structure. In the formula I propose, it’s dependent on your body fat percentage so if you have a high LBM, that’s totally fine. With the BMI, a large bone structure will probably indicate overweight/obesity. The BMI can be helpful when looking at population statistics, but not on an individual basis. That’s really the point I was trying to make.

  10. profile avatar
    Toni Jul 02, 2011 - 08:04 #

    Hi Marc.

    I recently found out that my LBM is about 97 lbs. and I’m 119 lbs. Is this a good number? My body fat is 17% and my BMI is 19.2 so those numbers are good (I’m told). Also, I’m 5’6″tall. Do I need to build more muscle or just maintain at this point? I’d love to lower my body fat percentage to like 15-16% but other than that I’m pretty satisfied with the way I currently look at this point. What do you think? I’d love to get your expert opinion. Thanks.

  11. profile avatar
    Ian Jul 24, 2011 - 18:11 #

    This formula works much better for me than the BMI or the one “Ketch Rudder” came up with.

    For me (5′ 10″) to make it into Ketch’s formula I’d have to maintain a BF% of less than 5. At 5′ 10″ I weight in at 195 and have just about 10%. His formula says that anything over 180 lbs is unhealthy for me. That simply cannot be right.

    That formula is much to simple to take into account all the varying skeletal sizes that people of the same height have. I have a friend who is my height and is much less “broad”. I have very broad frame (think defensive lineman).

    So this one you made up here is much more accurate per person. The BFFM diet also uses this formula and it’s very nifty.

    1. profile avatar
      Marc Perry Jul 24, 2011 - 20:46 #

      @Ian – Happy you liked the article. BFFM is a solid book and Venuto is a VERY knowledgeable guy.

  12. profile avatar
    Anonymous Sep 21, 2011 - 05:15 #

    Generally BMI is used in athletics to divide athletes into various groups. This is the best to know your fitness level.

  13. profile avatar
    Randy Oct 27, 2011 - 14:18 #

    Hello Marc, I’m 5’8 138 pounds and 23 years old. I’m on the skinny side and according to my BIA scale I’m around 12 percent body fat, not sure how accurate that is though. My goal is to reach 7-8 percent body fat, but my goal as is how much to actually weigh is where I get lost and confused. I know I need to gain weight and build muscle, but I just don’t know how much weight or muscle I should actually gain. I absolutely do not want a bodybuilders physique. My goal is to achieve a lean and muscular physique that of a fashion model, decent amount of muscle with low body fat. Any suggestions on how I can attain my goal? How much muscle or weight I should gain? thanks for any help and great website.

    1. profile avatar
      Marc Perry Oct 28, 2011 - 16:11 #

      @Randy – My suggestion would be to lose a little more body fat (let’s say a 5 pounds) without losing muscle and see if you are happy. right now your LBM is 121lb, so if you lose 5lb of muscle while keeping your LBM the same, your body fat will be around 8%. If you are not satisfied with how big you are, then you can add some muscle while being careful not to add to much fat. Check this out for more information on Ideal Weight.

  14. profile avatar
    Randy Oct 28, 2011 - 20:06 #

    Thanks Marc, and what is your suggestion on how much muscle is a decent amount of muscle to gain? 10 pounds, 15 pounds, or 20 pounds of muscle?

    1. profile avatar
      Marc Perry Oct 31, 2011 - 19:10 #

      @Randy – It really depends on your goals. Everyone is different. Gaining 20lb for me would simply be way too much in my opinion. My body wouldn’t feel great with that much more muscle. It’s hard to say what 10lb of muscle will look like in the right places on your body. You may be really happy with 5lb, or 10lb, or maybe it’s not enough. I do think 10lb is definitely a solid amount of muscle to add to your frame.

  15. profile avatar
    Nefaruru Nov 25, 2011 - 22:29 #

    This article didn’t say how much your minimum fat weight should be or can be, mine is 16.96 is it unhealthy to go lower?

    1. profile avatar
      Marc Perry Nov 26, 2011 - 12:55 #

      @Nefaruru – What is your total weight/height? I am unable to answer your question without knowing more information.

  16. profile avatar
    Nefaruru Nov 26, 2011 - 13:04 #

    I am 5 feet 5 inches and I weigh 105 pounds~ I have a scale that measures body fat percentage and it says 15-16% (depending on the day)

    1. profile avatar
      Marc Perry Nov 28, 2011 - 23:30 #

      @Nefaruru – The body fat percentage, not the total amount of fat in pounds is what’s most relevant. 16lb sounds sounds fine given you only weigh 105lb. Also keep in mind the BIA scales are notoriously inaccurate. If you can, see if you can find a competent trainer to take your body fat percentage. Hope that helpful!

  17. profile avatar
    Nefaruru Nov 28, 2011 - 23:48 #


  18. profile avatar
    cynthia S Jan 20, 2012 - 18:36 #

    Your article is so so helpful. I was always wondering what really was my ideal weight because im 5ft8 with a weight of 194 lbs and body fat of 32% but i really dont look obese as my BMI would say but more like a curvy woman with an hourglass shape, its always strange when people know how mu ch i weigh they are always surprised and tend to say i may have heavy bones so i dont know if thats d case, anyway now i know i need to be at 160 lbs to have a 20% body fat, so that i can finally see some definition on my stomach…so thank u, i now have a goal 🙂

    1. profile avatar
      Marc Perry Jan 21, 2012 - 11:04 #

      @cythnia S – Very happy you enjoyed the article and found it useful!

    2. profile avatar
      Sinead Mar 07, 2012 - 08:52 #

      I know what you mean Cynthia! People are always surprised how much I weigh (and so am I). I’m 5ft5 and weigh 135lb but I am very slim and you can see the muscles on my stomach and all over my body and people always comment on how fit I look and how slim I am. I’ve had other women come up to me in the club that I have never met and tell me how they had to tell me that I have the most amazing figure, so don’t get too worked up, I’m starting to think numbers aren’t everything. You probably look gorgeous, just the way any man would want his woman to look. I asked my boyfriend if he thought I would look better if I lost 5lb and he said no! He loves my bum too much! LOL

  19. profile avatar
    Aylissa Jan 22, 2012 - 20:30 #

    Hello! Thanks for having this helpful site. I just had a baby 🙂 I am completely uncomfortable with my body, weight n health overall. I am 33 stand at 5’4 and 180 lbs!! My body fat is 41.2 🙁 What should my ideal weight and body fat? Help

    1. profile avatar
      Marc Perry Jan 24, 2012 - 20:14 #

      @Aylissa – Congrats on your baby! That’s great news. I haven’t met too many women who feel slim and sexy after having a baby (i.e. I haven’t met any), so my guess is the emotions you are feeling regarding your body weight are quite common. With that said, I do think a focus on losing 0.5-1.5lb of fat per week like clockwork could be a great goal for you. My guess is a healthier body weight per BMI standards would be closer to 140lb. Body fat would be around 24%.

  20. profile avatar
    Erin Feb 04, 2012 - 19:11 #

    I am trying to figure out ideal body weight, but I can’t get the calculation to come out right? 156/15% doesn’t seem to equal 184. Hehe Sorry I know I’m probably doing something simple wrong!

    What is a healthy body fat % to be losing per month? I am 29, 5’5, & 140lbs, 27% body fat- I want to be leaner but muscular (not just lean and toned)- should I focus at staying this weight or be headed more in the 130 direction? Body fat around 24%? Does that sound reasonable for what I am trying to achieve?

  21. profile avatar
    Marissa Feb 24, 2012 - 01:38 #

    I went to the gym and found out I have 20% body fat I am a tall female and was told my ideal % is 15-17%. I was wondering if the chart on this site is for certain women or all. I am 23 if that helps.

    1. profile avatar
      Marc Perry, CSCS, CPT Feb 27, 2012 - 10:39 #

      @Marissa – Not sure who told you 15-17% body fat for a female is ideal, but that person may be misinformed, or telling you in the context of top fitness models. Yes, top female fitness models can be in the 15-17% range, but 20% sounds like it’s right on target with where you would want to be sustainably.

  22. profile avatar
    Sinead Mar 07, 2012 - 08:40 #

    Hi, I really like your articles. I walk everywhere and go to the gym 5 times per week for more than an hour at a time doing a mix of cardio, resistance and stretching. I’ve always been very active and I go out dancing in night clubs but I don’t drink or smoke. Before I went to the gym I did about the same amount of exercise and it was always varied, I’ve grown up doing a lot of dance, gymnastics and cycling. Yesterday I got my body fat calculated at the gym with one of those electrode machines. It said my body fat percentage is 26% which is in the average range. However, I am pretty fit and always have been, when I look in the mirror I see a pretty lean body, (I’m quite muscular for a woman), you can see my abs and the muscles in my thighs, my calf muscles are extremely defined when I am on tip-toes, when I stretch my arms out for a chest stretch you can see my ribs at the front of my chest although they don’t pop too much. I feel very fit, my fitness level is above most of my friends and I look good, I wouldn’t really want to lose any more fat because I think it would make my face too thin. I’m 24 by the way. I do have quite large boobs though but I don’t think they store much fat. Could it be that I store a lot more round my organs than under my skin on top of my muscles? If that is the case, could it be that the level of fat around my organs could be unhealthy? I worry slightly as there is a history of hear disease and liver failure in my family (although they were drinkers, I’m not).

    1. profile avatar
      Marc Perry, CSCS, CPT Mar 10, 2012 - 17:43 #

      @Sinead – By your description of your body, it sounds like your body fat is probably like 18-20%, not 26%. People in the fitness industry joke around about those handheld devices because they are completely inaccurate, especially the leaner you become. For more information, check out this article: . Finding a smart personal trainer to do a body fat assessment with a caliper will yield MUCH more accurate results.

      1. profile avatar
        Sinead Mar 10, 2012 - 20:46 #

        Thanks Marc! That would make sense…

      2. profile avatar
        Sinead Mar 10, 2012 - 20:55 #

        And you’re right Marc, I just searched and found photo examples of women at the various percentages and I think your estimation is pretty accurate, that’s what I look like! Amazing! Well done!

  23. profile avatar
    Sinead Mar 07, 2012 - 08:42 #

    I forgot to add I do eat a fair amount of cheese, otherwise my diet is very good, not much else high in fat.

  24. profile avatar
    Dawn Mar 08, 2012 - 15:12 #

    Thanks so much for this! I am a 36 year old woman. although I don’t rely solely on the scale, I figured my goal weight might be too low. My current weight is 198 lbs, my LBM is somewhere around 125 lbs, and fat mass around 73 lbs. (I used the bodpod for several months and am now measured with calipers.) My fitness regimen has been based heavily on strength training.( I started out at 102 lbs LBM and 94 lbs fat mass.) But I am now switching to more cardio while trying to maintain as much muscle mass as I can but I imagine I am going to lose a little at least. But this is immensely helpful.

    1. profile avatar
      Marc Perry, CSCS, CPT Mar 10, 2012 - 17:52 #

      @Dawn – Really happy to hear you enjoyed the article and congrats on your body composition improvements!

  25. profile avatar
    James Mar 16, 2012 - 23:26 #

    Like the website… So I always wondered what my bmi is right now I use to to be really big at about 320lbs with 49% body fat but since then ive gone through four years of football and two of basketball and lifting and running basically everyday now im down to 235lbs but it still says i have around 18% and the only place I really have fat now is my lower stomach does this sound right???

    1. profile avatar
      Marc Perry, CSCS, CPT Mar 25, 2012 - 22:03 #

      Hi James, how tall are you?

  26. profile avatar
    Rebecca Mar 24, 2012 - 12:41 #

    I was trying you ideal body weight calculations and I am not sure if I did it correctly. I am 5’10” 170 with a body fat of 35% ( sad to see that number with as much as I work out) 34 year old female. I believe for me to achieve the 24% body fat goal I would need to weigh 141… Is this correct? Thanks!

    1. profile avatar
      Marc Perry, CSCS, CPT Mar 25, 2012 - 22:41 #

      @Rebecca – I get 145lb, so you are not too far off. Your LBM is (170 – (170 * .35)) which is 110.5 then you take that number and divide it by (1-.24) which gives you 145lb.

  27. profile avatar
    Rebecca Mar 25, 2012 - 10:33 #

    One more question, would you suggest I increase my weight lifting during my weekly regimine? Right now I am doing cardio 3-4 times, lifting twice a week and following up with 1-2 classes of bikram yoga. Thanks for a great informative website.

    1. profile avatar
      Marc Perry, CSCS, CPT Mar 25, 2012 - 22:42 #

      @Rebecca – 2x per week sounds reasonable to me. In my humble opinion, that’s the minimum. 3 is the sweet spot for me, but again, 2 is absolutely ok as long as it’s full body or a lower/upper body spit.

  28. profile avatar
    Sarah Mar 30, 2012 - 22:12 #

    I’m a competitive swimmer, and have a lot of muscle on me. I’m the kind of person who’s BMI is overweight, but I have a healthy body fat percentage. I can’t help but think the body fat percentage calculator I use is wrong though. It says I’m close to having to much fat, so I tried to lose some fat, and now my hips and ribs are sticking out, I have a six pack, and I think I’m way too skinny. But my body fat is still at almost 30%! My coach is pressuring me to lose more fat and I need a reason why the body fat calculations he is using aren’t working so I can know if I should lose more fat or not.

    1. profile avatar
      Marc Perry, CSCS, CPT Mar 30, 2012 - 22:19 #

      @Sarah – It sounds like your body fat is closer to 15% than it is to 30%. That 30% number sounds way off by the description of your body. I would find a smart personal trainer (or two) ASAP to do a body fat caliper test. If you are using the BIA scales, or grips, they are useless as you get leaner and sometimes dramatically overestimate body fat. Here’s a link to learn more about body fat measurement – 5 Ways to Measure Body Fat Percentage. In my opinion, you should be using the 3, 4, or 7 site Jackson Pollock method with a skin fold caliper. Good luck and I hope your coach has a clue what he’s doing!

  29. profile avatar
    Aisha Apr 06, 2012 - 15:23 #

    Hi Marc, I have just measured my body fat percentage on some scales I have recently bought, I am female, 5,7 and weigh 10stones 4pounds. A couple of years ago I was almost 14stones so decided to drop the weight which I got down to 9stones 9pounds but after that my weight has started to slowly creep up! Apparently I’m 33% body fat and 49% muscle, surely that isn’t right too, definitely need some help! Thanks!

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 08, 2012 - 15:49 #

      @Aisha – I would get your body fat percentage done with a skin fold caliper. If your LBM is 105lb (about average for a 5’7” woman, that would imply your body fat percentage would be 29%. If your LBM is 110, then it drops to 25%.

  30. profile avatar
    Josh Apr 11, 2012 - 13:38 #

    Hey Marc, there’s one thing I still don’t understand. In the final equation, which look like this 156/(1-15%) = 184 pounds Where does that 15% comes from? I mean, it’s the 15% of the 200 lbs?

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 11, 2012 - 13:58 #

      Hey Josh, the 15% is the desired body fat percentage that you want. So at 184lb, you will have 15% body fat assuming your LBM is 156lb. The idea is that as long as you know (1) your current LBM and (2) your desired body fat percentage, then you will be able to figure out your “ideal” weight that you are targeting.

  31. profile avatar
    Barry O Apr 11, 2012 - 21:19 #

    My trainer has a scale with a device you hold in your hand which gives your weight, body fat, viserol fat and lean muscle, is this piece of equipment legit?

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 15, 2012 - 23:11 #

      @Barry ) – I don’t think so. It’s called BIA, except the electric current only travels through your upper body. Check out this article – 5 Ways to Measure Body Fat Percentage.

  32. profile avatar
    Lesa Apr 23, 2012 - 15:06 #

    Hey Marc – just discovered your website and great job! It’s really helpful.

    For the last three months I’ve been doing a lot of HIIT cardio (the Insanity program), trying to get muscle definition where I’ve always had fat – abs and thighs. I’ve gained a couple pounds of muscle and my endurance is better than ever but the stubborn fat won’t seem to come off. I’m 23, 125, small frame and my scale says 19% body fat. I wasn’t aware that this is on the low side of normal and the last thing I want is to be unhealthy. But I do know that I need to lose some fat to see the muscle I’ve worked my ass off to get. I was originally aiming to get down to around 13% BF – is this too low of a goal? What BF % would you suggest I aim for?

    Thanks for your help! 🙂

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 29, 2012 - 12:08 #

      @Lesa – Sounds like you are working hard, so congrats. Somewhere around 15-17% body fat for a women your age would be considered very lean, but not too lean. In my opinion, once you start getting under 15% body fat, then you may start experiencing unfavorable hormonal responses like stopping menstruation etc. Typically that happens around 12-13% bf. I would also get your body fat measured with a caliper as the BIA scales are not very accurate – see 5 ways to measure body fat percentage. At the end of the day, if you focus on losing fat without losing muscle, the fat will eventually come off your problem areas. Keep in mind it’s primarily a nutritional challenge, so you may need to take your calorie intake down in order to lose the excess fat. For many women who are looking to get very lean, somewhere around 1200 may work well. Check out this article for more info on calorie intake – How many calories should I eat to lose weight?. Good luck!

  33. profile avatar
    Yiannis Apr 24, 2012 - 11:56 #

    Hey Marc, your article’s really good sense. I’m 69″ and weigh 195 lbs. I’m coming down from 240 lbs three and a half months ago. I’m still losing, so I want to find my ideal weight. According to the BMI formula I should be between 130 and 170 lbs. According to the LBM method, I should be 163 lbs. Problem is that this seems way too little given that I have heavy bones. The weight I have in mind is between 180 and 183 lbs. I’ve a 22cm wrist perimeter and rank at the highest level of bone mass tests. How should I take this into account when I want to calculate my ideal weight?

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 29, 2012 - 12:13 #

      Hey Yiannis – What’s your current body fat percentage and height?

      1. profile avatar
        Yiannis May 01, 2012 - 23:24 #

        My height’s 69″ and fat percentage 30%

      2. profile avatar
        Marc Perry, CSCS, CPT May 07, 2012 - 09:34 #

        Yiannis – ok, so when you weigh yourself, you will then apply that information to the equation I provide.

  34. profile avatar
    mj Apr 24, 2012 - 23:29 #

    Okay, I’ve done the math, and I have 31lbs of fat to lose. What’s the best way to lose fat without losing muscle? I’ve read that you can lose fat or gain muscle, but you can’t do both at the same time (did I read that on this site?). How can I be reasonably sure I’m losing fat and not muscle?

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 29, 2012 - 12:23 #

      @Mj – every month, you can take your body fat percentage (See – 5 Ways to measure body fat percentage. I recommend using the skin fold caliper. Also, if you are eating ample protein (1 gram of protein per pound of body weight), strength training, and not creating a more than 35% calorie deficit, and not eating less than 50 grams of carbs, I think it’s unlikely you will lose muscle. So I use body weight as a proxy for fat loss assuming you are following a healthy exercise/nutrition plan.

  35. profile avatar
    Adam Apr 26, 2012 - 05:07 #

    Hello, I’m in agreement with mj, I want to lose about 36 lbs of fat (in about 6 months), and I am clueless, about the best way to do it. However I am determined.

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 29, 2012 - 14:03 #

      @Adam – The “best” way is to come up with a structured plan that you can stick to that incorporates some resistance training along with decreasing your calorie intake. Of course, I’m biased because I created my own program/plan (the BuiltLean Program), but creating a basic plan and tracking your progress will make it easier to stay on track towards your goals. I would also recommend tracking your nutrition intake even for a few days – See How to track calorie intake. I think it’s the best way to help change your eating habits for the long run. Good luck!

  36. profile avatar
    lv Apr 26, 2012 - 19:04 #

    I’m confused with this formula.. I’m trying to get my ideal weight

    1. profile avatar
      Marc Perry, CSCS, CPT Apr 29, 2012 - 14:08 #

      Ic – try reading over some of my answers to the comments and plug in your numbers into the equation. I hope to create a calculator at some point!

  37. profile avatar
    Lesa Apr 29, 2012 - 12:42 #

    Thanks, Marc! I had been restricting my diet to 1200 calories a day for the last two months but was seeing very little change. I have been eating very well and tracking everything that I consume. After reading more about calorie intake, starvation mode, and considering how sluggish I sometimes felt during workouts, I have upped my calories a bit to 1400ish. It’s a scary thing to do, since I’m so used to the thought of eating less to lose weight. However, the majority of the added calories is coming from a heartier breakfast and an added protein shake. I feel more energized through my workouts so hopefully this is the solution!

  38. profile avatar
    levi Apr 30, 2012 - 16:28 #

    I need you advise please if i clculate the lmb corectly? 1,75 m high, 47 years old.

    My weight is 80 kg, my fat precantage is 25%, I would like to be in 15% fat only. the calculation is as follow:

    80-(80*0.25)= 60

    60/(1-0.15)= 70.5 the best wight, isit correct?? thanks

    1. profile avatar
      Marc Perry, CSCS, CPT May 07, 2012 - 09:21 #

      @levi- Yes, the answer is 155lb, or 70 kilograms.

  39. profile avatar
    Terra May 01, 2012 - 07:44 #

    I’ve never liked the results according to the BMI scale. I am an athletic female, I have always been one and I lift heavy weights and carry alot of muscle but according to the BMI scale, I would be considered obese. Every 3 months I have my body fat % done by a personal trainer. This is much better and puts you in a more positive frame of mind if you’re someone like me. I stay around 27% body fat which is considered normal/average. I suggest to anyone that’s on any kind of weight loss regime to not only weigh BUT have someone do your body fat % on a regular basis as well. You may not see results or pounds lost like you want on the scale but if you’re incorporating weights into your program, you may gain muscle and lose inches of fat. I know I may only drop a few pounds sometimes but the calipers never lie! Get yourself pinched! 🙂

    1. profile avatar
      Marc Perry, CSCS, CPT May 07, 2012 - 09:22 #

      Thanks for sharing Terra!

  40. profile avatar
    Barbara May 02, 2012 - 12:20 #

    Hi Marc,

    I’ve been working hard since January – gym (weights, plus a little cardio) 3x weekly plus healthy eating – and have so far dropped 45lb, from 301 down to 256. The last month or so I have started introducing some high intensity intervals within the cardio, but obviously have to take it gently owing to my size. I am 5’7″, 48 yo female.

    My body fat scale tells me that, give or take, I’m around 50% body fat – so around 128lb lean. Using your formula and a desired BF% of between 25-29%. Would leave me weighing somewhere in in the range 164 to 180, which seems kinda heavy. Any comments?


    1. profile avatar
      Marc Perry, CSCS, CPT May 07, 2012 - 09:49 #

      @barbara – as you lose weight, you will also lose water as well, which is technically part of your LBM. Also, you will probably lose a little muscle (which is ok because you won’t need as much muscle with a much smaller frame). The 164-180 sounds about right, but again, my guess is your LBM may decrease below 128, it will likely be around 110-115. That’s my best guess. Keep up the great work!

  41. profile avatar
    amy d May 18, 2012 - 19:17 #

    I enjoyed the article. I am working (dietitian)with a very fit 35 year old recreational athlete who regularly cycles 3 hours, competes in triathlons. A trainer measured her fat with 9 sites and got 24.5. She is 142 pounds, almost 5 7. She wants to look long and lean but is built muscular. wants to lose weight but burns 500-600 cal per day (wears monitor) 1300 caLs/ long rides. What would you say about a body fat goal- maybe 20-22%?

    1. profile avatar
      Marc Perry, CSCS, CPT May 24, 2012 - 10:39 #

      @amy d – I think a 20-22% body fat goal make a lot of sense, maybe even leaner if she is competitive. I wrote an article about the impact of body fat on athletic performance – How To Run Faster | #1 Tip You’ve Never Heard.

  42. profile avatar
    Rachel May 30, 2012 - 20:26 #

    *sigh* I get so confused. I get into raging arguments with my doctor that I absolutely have to lose 20-25lbs according to the BMI chart that she swears by.

    I weigh 180lbs (5’8″, early 30’s). Multiple measurements multiple times by people trained to use calipers put me at ~20% body fat. I work out hard with high-intensity circuit workouts several times a week (swinging up to 40kg kettlebells, etc.). I run, mostly trail and hill workouts, and I bike 26 miles roundtrip 2-3 times a week. I ride horses. I record meals (15-1700 calories a day) and rarely eat processed or take-out food.

    Before I was this active (5-6 years ago), I DID weigh 30lbs less. My doctor harps every time I see her that I’m unhealthy. She thinks that surely if I just work out more or longer I should be able to just lose more weight.

    Sure, I’d love to wear a smaller size. But realistically, what more can I do?

    1. profile avatar
      Chelsea May 31, 2012 - 23:49 #

      Rachel, I have a very similar problem! I am also 5’8” and my lean body mass is 146 (calculated by multiple formulas using the skin fold method). I know that must be quite high for a woman… but then again I have always been freakishly strong, large-boned, etc… everything about me, down to my shoe size is just bigger than typical. 20% puts me around 180. *shrug*

      1. profile avatar
        Chelsea May 31, 2012 - 23:56 #

        And if I’m not wrong about this (and I don’t think I am…), it really bugs me that all of my adult life I’ve been told over and over again my ideal weight is in the range of 145-160… that I was made to feel bad over not being able to attain an ideal that was never really healthy for me anyway…

      2. profile avatar
        Marc Perry, CSCS, CPT Jun 03, 2012 - 17:12 #

        @Chelsea – Yes, I agree, that is unfortunate. But now you are armed with good information.

      3. profile avatar
        Marc Perry, CSCS, CPT Jun 03, 2012 - 17:11 #

        @Chelsea – Being strong and fit is a great thing for men and women. That’s my take.

      4. profile avatar
        Rachel Jun 06, 2012 - 15:27 #

        @chelsea – Wish more people accepted this.. I’m so tired of being told that I just need to eat ‘less’ (calories, fat, etc.) and then I’ll be able to wear smaller clothing sizes. But I LIKE having a body that I can trust not to fail me when I want to do things requiring strength!

        Looking forward to the next fight with my dr… 😉

    2. profile avatar
      Marc Perry, CSCS, CPT Jun 03, 2012 - 16:34 #

      @Rachel – As I discussed in the article, BMI is inherently a faulty framework when applied on an individual basis. If you have a large bone structure and a lot of muscle, then that’s how you are built. It sounds like your doctor is essentially telling you (whether she understands it or not) to lose a bunch of muscle, which I don’t think is a good idea. My opinion is be proud of the muscle you have because it’s actually quite unusual for a woman of your height to have that much muscle and my guess is as you age, it will serve you well to help protect your body against degeneration in terms of functional movement.

  43. profile avatar
    caroline May 31, 2012 - 12:06 #

    So sorry it appears I am dense both literally and figuritively, I cannot do this maths it’s the (1-24) bit? I am 5.4, 184 ilbs and 36.1 % body fat, I am 36 yrs old.
    Love this site though so very sensible and intelligent it’s my new best friend for health. thanks.

    1. profile avatar
      Marc Perry, CSCS, CPT Jun 03, 2012 - 17:00 #

      Hi Caroline, your ideal body weight assuming 25% body fat is 140lb. Your LBM is 117lb (184 – (184 -184*.336)). I need to add an ideal body fat calculator to make this easier for everyone.

  44. profile avatar
    Diana Jun 01, 2012 - 14:47 #

    Hi Marc,
    Your formulas make good sense to me, except I’m not sure how to calculate my own ideal weight given that I am underweight and prone to muscle injury, so I am trying to gain both fat and muscle.

    I am 5’7″, female, 29 y/o with 106.2 lbs body weight, and a body fat percentage of 18.3%.

    How do I know how much muscle weight to add? This will contribute to my ideal body weight and I know that after I have that calculated, I can basically say my fat percentage should go up to about 21% of my ideal body weight. Hope you can help! Thanks!

    1. profile avatar
      Marc Perry, CSCS, CPT Jun 03, 2012 - 17:37 #

      @Diana – well you can establish a target LBM and target desired body fat percentage, then solve the equation. That’s a decent starting point. You can also work backwards like getting up to 115lb and adding 50% muscle/fat, then take our your LBM and divide your new LBM by 115 to get your new body fat percentage.

  45. profile avatar
    Adam S Jun 03, 2012 - 16:56 #


    I am 5’6″ 180 lbs male, 24% body fat using the navy formula. According to that I should have 135 lbs lean mass, but I am bony in many areas and feel generally weak. I used to be over 210 lbs at one point, but I felt much stronger than I do now.

    And a little bit of history – is that I went from over 200 lbs to 155 lbs in a very short amount of time eating very little – 1200 or so calories and sometimes less. Afterwards I was determined to gain weight because I felt so WEAK. but I didn’t do it correctly.

    An ideal body weight for my height is 146-164 which is between 10-19% body fat with my lean body mass seems to match up.

    Bu I am just worried how much I damaged my body and do I need to be still concerned with putting on more muscle or not?!

    1. profile avatar
      Marc Perry, CSCS, CPT Jun 07, 2012 - 09:41 #

      @Adam – I think 135lb lean body mass for someone your height is actually completely normal. I’m hard-pressed to believe you would be “bony” if you lost all the fat you have to reveal your lean muscle. My guess is you would look muscular. Strength is more a matter of neuromuscular efficiency and less big muscles. What I mean is that you can get A LOT stronger without getting bigger, because your brain sends nerve impulses to your muscles, which can become more efficient and recruit more muscle fibers. Think how powerlifters can be stronger than bodybuilders double their size. I plan on writing a longer post on how to get stronger in the next couple months.

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