BMR Formula Comparison Calculator
Compare Mifflin-St Jeor, Harris-Benedict and Katch-McArdle.
Enter your values
ⓘ Live results
Results
- Mifflin-St Jeor
- 1,768 kcal
- Harris-Benedict (revised)
- 1,844 kcal
- Katch-McArdle
- 1,752 kcal
- Average of three
- 1,788 kcal
Quick answer
The three common BMR formulas usually agree within a few percent, with Katch-McArdle needing body fat percentage.
Mifflin-St Jeor, revised Harris-Benedict, Katch-McArdle (370 + 21.6 x lean mass)
How to use the BMR Formula Comparison Calculator
- 1Enter your stats — body fat is only needed for the Katch-McArdle estimate.
- 2Mifflin-St Jeor is generally considered the most accurate for the general population.
- 3Use the same formula consistently over time so your comparisons stay meaningful.
Worked example
Using the values the calculator loads with:
Inputs
- SexMale
- Weight80 kg
- Height178 cm
- Age30 years
- Body fat20 %
Results
- Mifflin-St Jeor1,768 kcal
- Harris-Benedict (revised)1,844 kcal
- Katch-McArdle1,752 kcal
- Average of three1,788 kcal
Frequently asked questions
Why do formulas disagree?
They were derived from different study populations, so equations weight height, weight and age differently.
Which should I trust?
Mifflin-St Jeor is the modern default; Katch-McArdle can be more accurate if you know your body fat precisely.
About this calculator
- Built and reviewed by James Whitfield · How we build and test calculators
- Report an error
Results are estimates for general information. For medical, legal, structural or financial decisions, confirm with a qualified professional.