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How to Calculate Your Calorie Burn

By Marc Perry / June 29, 2017

In my free Get Lean Guide report, I wrote that eating less calories than you burn is one of the 3 pillars of effective fat loss nutrition. Calorie control is so important because if you eat more calories than you burn, you gain weight, and if you eat less calories than you burn, you lose weight.

So how do you accurately measure your calorie burn? Is a simple calculation really good enough?

What Is Your Calorie Burn?

Your calorie burn is the sum of three components:

1) Basal Metabolic Rate (BMR) – This is how many calories your body burns at rest. Even while you rest, your respiratory system is operating, digestive system, and other body processes that require energy (i.e. burn calories). Your BMR represents roughly 65% of your total calorie burn.

2) Activity Level – This is how many calories you burn that requires physical movement, or when your body is in motion. The more active you are, the more calories you will burn. Activity level represents roughly 20% of calorie burn, which depends on how active you are of course.

3) Thermic Effect of Food – Digesting food requires energy, but typically the thermic effect of food only adds up to about 10% of the total amount of calories you burn.

Calorie Burn Method #1: Harris Benedict

Most calorie burn calculators found on the internet use the Harris Benedict (HB) method, which takes into account your age, weight, height, and sex to arrive at your BMR. But we still have to figure out your activity level, so that BMR value is multiplied by an “Activity Multiplier” to get your total calorie burn (see equation at bottom of post). The thermic effect of food is already reflected in your BMR calculation.

Notice that the HB method does not take into account your body composition. Individuals with more muscle tend to be more metabolically active and burn more calories. The HB method overestimates calorie burn for individuals with a high body fat percentage and underestimates calorie burn for those with low body fat (and thus more muscle). While it’s not perfect, the HB method is a very helpful starting point.

Calorie Burn Method #2: Katch & McArdle

The Katch and McArdle (KA) method takes into account your body composition to arrive at your BMR and for that reason is considered to be more accurate. The KA method uses the same activity multiplier as the HB method, but has a big downside of its own. The KA calculation depends on your body fat measurement, which may not be accurate (depending on what type of body fat measurement you are using). I would definitely take the KA method over the HB method, but they usually only vary for the average person by a few hundred calories on the high end (for KA equation, see bottom of post).

Calorie Burn Method #3: Measure BMR & Activity Level

A more precise way to measure your BMR is with a metabolic analyzer. If you fear you have a very slow metabolism, this may be a smart idea for you. How it works is you breathe into a tube for around 10 minutes and the analyzer gives you a reading. Because a Metabolic Analyzer can cost thousands of dollars, it’s best to try to find a nutrition practice, or hospital that charges for the test per reading (usually around $150). Even the metabolic analyzer has its drawbacks because your BMR can fluctuate depending on a number of factors. Still, it’s considered the gold standard of BMR measurement.

The best way to measure your activity level is using a calorie tracker like the BodyBugg and FitBit, which attempt to measure your movement with accelerometers. None of these trackers is scientifically proven to accurately measure calorie burn and they range in price from $99 to $299. A couple challenges these trackers face is measuring your calorie burn when cycling on a bike, or weightlifting. I think these calorie trackers are definitely interesting and have potential, especially as a motivational tool to help people to get off the couch.

So how the heck do you accurately figure out your calorie burn if your BMR is a moving target that’s tough to assess and your activity level is just as challenging? In my opinion, starting out with the HB/KA methods will give most people a very good idea of calorie burn, but ultimately you need to validate them with measurable results (i.e. weight loss, or weight gain).

Calorie Burn Equations

Harris Benedict Method

BMR Men: = 66 + (6.23 X weight in pounds) + (12.7 X height in inches) – (6.8 X age)

BMR Women: = 655 + (4.35 X weight in pounds) + (4.7 X height in inches) – (4.7 X age)

Katch & McArdle Method

BMR (Men + Women) = 370 + (21.6 * Lean Mass in kg)

Lean Mass = weight in kg – (weight in kg * body fat %)
1 kg = 2.2 pounds, so divide your weight by 2.2 to get your weight in kg

Activity Multiplier (Both HB + KA Method use same activity multiplier)

Little or No Exercise, Desk Job 1.2 x BMR
Light Exercise, Sports 1 to 3 Times Per Week 1.375 x BMR
Moderate Exercise, Sports 3 to 5 Times Per Week 1.55 x BMR
Heavy Exercise, Sports 6 to 7 Times Per Week 1.725 x BMR

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57 Comments

  • erum says:

    aoa i m working in an iphone app in which i m using running,walking,jogging mode i m going to use GPS to track user's distance covered ,duration of either walk , jogg,run etc pls tell me any recommended equation so that i can calculate calories burned by a person i think formula needs "weight" , "duration of exercise" "speed", "distance covered" pls let me know about formula i m googling it but failed to get any good formula ........................

    • Marc Perry, CSCS, CPT says:

      @erum - There are a ton of different equations, but the only one I can remember off the top of my head is based on metabolic equivalents, or MET. You would have to figure out a way to express the activity and the speed in terms of MET. For example, running 6 minutes per mile has roughly a 16.3 MET whereas 10 minutes per mile is 10.2. You can look online for charts. The equation is (METS x 3.5 x body weight in kg)/200 = k/cal per minute

  • KeeG says:

    Hi Marc,

    I just found all of your wonderful information. I am 5'3", 154 lbs. My goal is to lose 15lbs. My BMR shows 1442 and with activity (1.375) is 1982.75. I have been on a 957 calorie diet and have not seen much improvement. I burn around 1200 calories a week in cardio. Should I increase my daily caloric intake? What percentage of Fat, Protein & Carbs are reasonable?

    Thank you!

    • Marc Perry, CSCS, CPT says:

      @KeeG - thanks for the kind words. I don't know is the short answer. Sounds like you need to trouble shoot your calorie level. Somewhere around 1200-1300 calorie intake sounds more reasonable given your body size. Check out this post for protein/carbs/fat breadkdown - Best Macronutrient Distribution For Fat Loss? | Q&A Weekly Roundup

  • Bill Mitchell says:

    This makes no sense. I am 52, weigh 259 and am 6'5". Supposedly my resting BMR is 2300. I exercise 1 to 3 times per week. I am here to tell you that if I even ate 2300 cals a day I would weight 400 lbs by the time next year.

    How the heck can these numbers be right? I know from 52 years of eating experience that 2300 cals a day is WAY WAY WAY too much for me to lose weight. With my exercise level I am supposed to be able to wolf down 2100 calories a day and still lose 2 lbs a week.

    I am here to tell you, there is no way. I've eaten that much before. I get FAT.

    • Marc Perry, CSCS, CPT says:

      @Bill Mitchell - I need to write an in depth article on metabolism/genetics because some people have lower metabolisms than others. It does sound very surprising to me that you would be unable to lose weight on a 2000 calorie diet, but it sounds like you know your body. You may consider getting your BMR checked out (there are machines that measure BMR as I showed in the article) and consulting a nutritionist to see what he/she has to say.

  • Bill Mitchell says:

    Ugh. All I can say is ugh.

    I have tried everything. I've cut out all processed carbs, cut out all diet soda, cut out cereal. I am seesawing my calories between 1800 and 1400 a day. I am taking a 1/2 hour walk every day.

    I have now weighed exactly 259 for 10 days! WTH? I was especially good yesterday. Ate only lean meat and vegetables. Had plenty to eat and came in around 1350 calories. Wasn't hungry at all. Had been excited because I had finally broken below 259 the other day to 258. This is it finally! I thought.

    But this morning back to 259! Seriously, I am a 6'5", 259 lbs (large frame - I look slim in clothes at this weight - just a little soft shirtless but by no means fat), how do I GAIN a pound on 1300 calories? My BMR just breathing is 2000 calories a day.

    It is as I am somehow defying the laws of thermodynamics.

    The weird part is that I went from 269 to 259 just like that, But for some bizarre reason, 259 is a steel plated, kevlar coated kyptonite drenched wall of concrete. I have now been on a great diet plan for 10 days and have not lost 1 single ounce. My metabolism is clearly completely dead (and yet I feel fine).

    • Marc Perry, CSCS, CPT says:

      @Bill - It's only been 10 days, so I would consider 20+ days as a plateau. Could be water, sodium, glycogen etc. that could keep your weight a little higher. I would recommend taking a longer term outlook toward reaching your fitness goals. Maybe create short term goals of losing 1-2lb per week, and longer term goals as well. The point is that losing weight and changing your body is a marathon, not a sprint. Finally, if you haven't checked out my free Get Lean Guide, I would check that out if I were you. The exercise portion may be particularly helpful. In my experience the magic happens when you have a great nutrition plan AND a great exercise plan.

      • Bill Mitchell says:

        Calorie wise people would say I'm in "starvation mode" but I hardly think eating 3 full meals and 2 snacks is starving. I was stuffed after every meal.

      • Bill Mitchell says:

        @Marc,

        Thanks. I think part of the problem may be that I am a colon cancer survivor and ever since then (4 years ago), my testosterone has been very very low (like a reading of 65 or something). Most me my age are around 350 I think.

        The doctors cannot figure out why my testosterone is so low. The testes seem to be working fine. They believe that for some reason, the gland that tells the testes to make testosterone isn't sending the signal.

        However, I do not have any signs of low testosterone. I am energetic (for a 52 year old) and have no sexual dysfunction at all. I grow a normal beard (have to shave daily) and have a rather deep male voice. I "look" in the picture of health.

        I don't know, it is all quite weird. This is what I ate today:

        Breakfast:
        Raisin Bran with Splenda
        2% milk

        Snack:
        Banana

        Lunch:
        Baked pork chop
        Broccoli
        Apple sauce

        Snack:
        1/4 Cantaloupe

        Dinner:
        Baked chicken
        Spinach
        Cucumber salad with light balsamic dressing
        Yogurt

        About 5 glasses water.

        No soda, no processed carbs.

        About 1300 calories but ate PLENTY - 3 full meals and 2 snacks. This is how I eat every day but lose no weight.

        • Marc Perry, CSCS, CPT says:

          @Bill - I really need to revise the calorie post because there is more to losing fat than just eating less calories. As you are experiencing, hormones can have a huge impact. my best guess is your low testosterone level is seriously affecting your ability to lose fat. I have a large article database with articles that we plan to write and testosterone is a topic we plan on covering in depth, but at this time it has not been written. With that said, I would consider natural ways of helping increase your testosterone to see if that helps. One more thing, I would consider eating eggs in general instead of dairy/grains in the morning. I used to eat dairy/grains for years in the morning, until i finally realized it was wreaking havoc on my digestion. Also has a pretty huge affect on insulin as well. You should certainly consider talking to your doctor about testosterone, as well as a naturopathic physician and compare what they say.

  • Bill Mitchell says:

    The sad part is I am still 45 pounds from my goal weight. Is it going to take me a month of dieting to just lose a pound at a time only to have it reappear for no reason out of the blue? Is this the body I get from now on no matter what?

    And before anyone says "maybe you are in starvation mode", I'm not. I'm not hungry. I am eating lots. If you cut out bread and starches and dairy from your diet, 1500 calories is a A LOT of food (for instance, that's about 15 chicken breasts - who could say someone eating 15 chicken breasts a day was "starving"?)

    My meals are healthy, well balanced, drinking plenty of water, no soda, getting exercise.

    How, seriously how?

  • dee says:

    can you help me , am 41, 5 foot 3 inches, 160 lbs, moderate exercise, how many calories should i eat to loose weight?

  • Jamie says:

    Mark. Thanks for the great site an all the info. I am back on by weight loss journey once again. I have gained and loss weight for the past 10 years. I've gone from lowest of 185 to the highest of 260. I know that I know, when I am eating clean, eating under 2000 calories is very doable. If I work out 3 to 5 times a week, I can slowly lost weight. However, based on these numbers and my high weight at the moment, I am supposed to be eating 2500 calories. I just can't wrap my mind around that. I really think that extremes of up and down dieting have fried my metabolism. What is the worse that can happen if I stick to around 1800 calories and work out about 5 times a week? Workouts would be a couple of 2.5 mile runs and about 3 lifting sessions. I always take a good amount of protein after workouts.

    • Marc Perry, CSCS, CPT says:

      @Jamie - I need to update my "How Many Calories Should You Eat To Lose Weight" post, because individuals who have more fat to lose can get away with more aggressive low calories diets than those who are already getting leaner. So 1800 calories should work fine. Of course, yoyo exercising/eating is a major issue, so I hope that as you lose the weight this time it will be more manageable for you!

  • Jemma Benns says:

    Hi there ! Thanks so much for the informative articles.

    I am a 20 year 5 ft 10 old female, I did weigh 260lb in May this year but have managed to get myself down to 210 so far from calorie counting and exercise 3-4 days a week.

    I made a bas mistake when I first started though of only eating 800 a day on top of exercising and I have a very active job as well where I am on my feet doing hard cleaning for 4 hours a day, and my weight loss stalled and I actually put on weight.

    I looked more into BMR and so on after this and didnt realise you had to eat at least your bmr to lose weight.

    Anyway what Im saying is I wanna accurately work out what I need to eat and how much. I worked out using the Harris Benedict method my BMR is 1803 for my sex and height, and as I exercise 5 days a week now as well as having an active job I put my activity multiplyer as moderate and added my bmr into it and it came out as 2794.

    So I was just wondering, is this the amount I have to eat per day in order to healthily lose weight ?? It just seems very high to me, Im currently eating around 1500 and a little extra depending how many calories I burn off through exercise (usually burn about 800 a day from exercise) so I eat an extra 800 on top of 1500.

    I just wanted to clear it up and make sure I am doing it right :) Im a little confused as to 2794 is how many I should be eating.

    Thanks in advance !!

    • Marc Perry, CSCS, CPT says:

      @Jemma Benns - I need to update the how many calories should you eat to lose weight post, but I think for those people who have a good 30lb+ to lose, eating less calories than BMR is absolutely ok. It's not a hard and fast rule. The idea is still to get the proper nutrients you need (vitamins and minerals) even with less food while not getting too hungry so you can sustain the diet. Good luck!

  • Christine says:

    QUESTION: I'm a metrics person and wanted to know "WHAT ABOUT THE OTHER 10%?" (the article starts out noting 65%+20%+10% as the 3 ways burn occurs but it's short by 10%... is there actually a 4th way it burns or are these 3 percents off?

  • Robt Porterfield says:

    What's up, yeah this piece of writing is genuinely nice and I have learned lot of things from it on the topic of blogging. thanks.

    • Kristin Rooke, CPT says:

      Glad to hear it, Robt! Our goal is to educate, so we're stoked to hear you're gaining value from our articles.
      -Kristin, BuiltLean Coach & Managing Editor

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