Resting Metabolic Rate: how many calories do I burn in a day

The answer to the question “How many calories do I burn in a day” is your resting metabolic rate + any additional calories you burn with exercise. In this post my objective is to show you how to calculate your daily calorie requirements and then provide some calorie deficit options to burn fat. At the end of the post, based on the calorie level you choose, you will be able to estimate how long it will take to reach your goal.

[When people get this technical asking me about resting metabolic rate, about calories burned walking, questions like "how many calories do I burn in a day?", they are usually looking for single digit body fat like the woman in this image.]

Step 1 – Calculate your RMR

Resting Metabolic Rate Equation – Metabolic Rate Calculator
9.99 (weight in kg) + 6.25(height in cm) – 4.92 (age) + 166 (0 if female, 1 if male) -161
To calculate your weight in kg, divide your weight in pounds by 2.2.
To calculate your height in cm, take your height in inches X 2.54

Step 2 – Estimate your calories from exercise and add them to your RMR

How many calories does walking or running burn
To calculate how many calories you burn walking , take your weight and multiply it by 0.30 for every mile walked. For example, a 200 pound man burns 120 calories walking two miles. 2 miles X 200 lbs X .30.

For running, estimate your weight in pounds by 0.63. For example, a 200 lb man would burn 126 calories per mile (200 X .63).

Step 3 – Choose your level of calorie deficit

Most people try to maintain a 500 calorie deficit to lose a pound every week.

An example to put it all together

Here is how this would play for a 200 lb six foot, one inch, 44 year old male:
Step 1 – Calculate resting metabolic rate
9.9(200/2.2)+6.25(73 X 2.54) – 4.92(44) + 166 -161 = 1855.58
So he would burn 1855.58 calories just living.

Step 2 – Estimate and add calories from exercise
Assume he runs 3 miles per day
200lbs X 0.63 X 3 miles = 378 calories burned running
1855.58 RMR + 378 calories from activity = 2233.58 active metabolic rate.

Step 3 – Choose calorie level
Eat 1700 calories – 2233 = 533 daily deficit, 3735 weekly deficit, ~1 pound weight loss every week.
Eat 1000 calories = 2.5 pounds per week
Eat 500 calories = 3.5 pounds per week
Eat 275 calories = 3.91 pounds per week.

Eating only 275 calories a day is way too low but I used it as an example because that is what Christian Bale used to cut weight for his role in the movie The Machinist.

[To lose 63 pounds in four months Christian Bale ate only an apple and a can of tuna each day for 275 calories]

Here are some additional definitions to help explain resting metabolic rate…

Resting Metabolic Rate Definition
Your resting metabolic rate is the number of calories your body uses at rest. It is the number of calories your body burns just keeping you alive.

Basal Metabolic Rate
Basal basal metabolic rate is another term for resting metabolic rate – the base rate at which your body burns calories for basic metabolic functions keeping you alive like maintaining internal temperature, repairing cells, pumping blood and powering muscles at rest.

Measuring Metabolic Rate
Here is my example, I am 44, 6″1, 203lbs so the equation for me is:
9.99 (203 / 2.2) + 6.25 (73 X 2.54) – 4.92 (44) = 166 – 161 = 1869.2

Active Metabolic Rate
Your active metabolic rate is your resting metabolic rate with the addition of any activity you include in your life like daily workouts. This is the real number you burn through in a day and is the number you should use to determine how many calories you can consume while remaining in a calorie deficit.

Daily Caloric Needs – How many calories do I need in a day
Active metabolic rate (resting metabolic rate + additional activity) tells you your daily caloric needs. If you want to lose weight you reduce your intake from this number, or the opposite if you are gaining muscle.

How many calories in a pound
You need a 3500 calorie deficit to burn a pound.

How Many Calories should I eat
If you are trying to run a calorie deficit, try to cut 1000 calories off your active metabolic rate. That way you run a deficit of 7000 in a week which translates into about two pounds.

You can now answer the question how many calories do I burn in a day using your resting metabolic rate calculation and your estimate of additional calories burned exercising and added through eating.