BMR Calculator
What your body burns at complete rest. Three accepted equations are shown side by side, because they disagree by a few hundred calories and it is worth seeing that.
How the math works
Mifflin-St Jeor: 10 x kg + 6.25 x cm - 5 x age, then +5 for men and -161 for women. Harris-Benedict (revised): 88.362 + 13.397 x kg + 4.799 x cm - 5.677 x age for men; 447.593 + 9.247 x kg + 3.098 x cm - 4.33 x age for women. Katch-McArdle: 370 + 21.6 x lean mass in kg, where lean mass is weight minus the fat.
Common questions
- What is BMR?
- The energy your body uses to stay alive at complete rest: breathing, circulation, keeping warm, running your brain. It is typically 60 to 70 percent of everything you burn in a day.
- What is the difference between BMR and TDEE?
- BMR is at rest. TDEE adds everything you do - walking, working, training, even digesting. TDEE is BMR multiplied by an activity factor between 1.2 and 1.9, and it is the number that decides whether you gain or lose weight.
- Which equation should I use?
- Mifflin-St Jeor unless you have a measured body fat percentage, in which case Katch-McArdle. If your body fat number came from a bathroom scale, treat it as a guess and stay with Mifflin.
- Should I eat my BMR?
- No. Eating at BMR means eating less than you burn every single day, because you are not in a coma. Use TDEE as the reference and take a deficit from that.
- Can I raise my BMR?
- A little, and slowly. More muscle raises it, since lean tissue costs more to keep. Crash dieting lowers it. The effect of either is modest compared with how much you move.