BMR Calculator
Resting calorie estimate from age, sex, size.
Loading tool
BMR is an estimate of calories burned at complete rest. Equations disagree. Use the result as a starting point, not a prescription.
How to use this tool
- Enter your measurements. Use the units shown on the labels. Do not send medical data anywhere.
- Read the estimate. These formulas are public rules of thumb, not a diagnosis.
- Talk to a clinician for decisions. Do not change medicine, diet, or training from this page alone.
Equations
Mifflin-St Jeor is the default. Harris-Benedict is offered for comparison. Both are population regressions, not lab calorimetry.
Frequently asked
Should I eat exactly this many calories?
No. Daily need also depends on movement. See TDEE. This is not diet advice.
Why do sex options change the number?
The published equations use different constants. They are rough population fits.
Is Katch-McArdle available?
If you type a body-fat percent, a lean-mass variant is shown as another estimate.
Can I use this BMR as a clinical calorie order?
No. Equations are population estimates, not medical advice.
Do medications change BMR?
They can. This page cannot account for that.