Calorie Calculation Formulas

This post is a resource dedicated estimating your daily calorie maintenance. Remember that no calculator can pinpoint your exact calorie maintenance because there are too many factors to consider, and most methods have a degree of error, however you can get an estimate with a few formulas. 

If you’d rather have it all done for you, check out the calorie calculator at the bottom of this post.

To use these calculators you’ll need to have the following information handy;- 

1. Weight (lbs and kg) 
2. Height (I’m) 
3. Age  
4. Sex 
5. Activity level 

Activity level guide 

Sedentary- little to no exercise  

Lightly active- little exercise 1-3 days a week 

Moderately Active- moderate exercise 3 to 5 days a week 

Very active- intense exercise 6 to 7 days a week 

Extremely active- intense daily exercise and strenuous physical job 

Basic calculator  

This is the easiest calculator to use. Just multiply your current body weight in pounds by 14-16. Going with a number closer to 14 if your weekly activity is on the low side and closer to 16 if your activity is on the higher side. 

That means you multiply your body weight by: 

14 if you’re Sedentary  

14.5 if you’re Lightly active 

15 if you’re Moderately active 

15.5 if you’re Very active 

16 if you’re Extremely active 

The Harris-Benedict formula 

The formula takes into account: 

1. Height 
2. Sex 
3. Age 

To find your Basal Metabolic Rate which is the number of calories you burn at rest (just by being alive) 

To do that: 

Men: (10×weight in kg) + (6.25×height in cm) – (5×age in years) + 5 

Women: (10×weight in kg) + (6.25×height in cm) – (5×age in years)- 161 

After finding your Basal Metabolic Rate (BMR) use the following activity multiplier  

Sedentary: 1.2 

Lightly Active: 1.375 

Moderately Active: 1.5 

Very Active: 1.675 

Extremely Active: 1.8 

Katch Mc Ardle Formula 

This is the most precise method.. That’s because it takes into account lean body mass. This also makes the formula useful if you’re on the overweight side.  

For this formula to work you’ll need to know your lean mass (in KG) and therefore your body fat percentage. 

Use the following formula to calculate your BMR. 

370+(21.6×lean mass in kg) 

After you get your BMR multiply it by the activity multiplier below: 

Sedentary: 1.2 

Lightly Active: 1.375 

Moderately Active: 1.5 

Very Active: 1.675 

Extremely Active: 1.8  

Automatic Calculator

If you’re like me and don’t like the hassle, just use this calculator I provided below