BMR Calculator
Calculate your Basal Metabolic Rate — the calories your body burns at complete rest just to maintain basic physiological functions.
How to use the BMR Calculator
- Enter your inputs into the BMR Calculator above.
- Results update instantly as you type — no submit button needed.
- Adjust any value to see how the result changes in real time.
The Mifflin–St Jeor BMR formula
Men: BMR = 10·W + 6.25·H − 5·A + 5 · · · Women: BMR = 10·W + 6.25·H − 5·A − 161
W is weight in kg, H is height in cm, A is age in years. Mifflin–St Jeor is the modern standard, generally more accurate than the older Harris–Benedict equation.
Worked example
A 30-year-old man weighing 80 kg at 180 cm: BMR = 10×80 + 6.25×180 − 5×30 + 5 = 800 + 1,125 − 150 + 5 = 1,780 kcal/day. A 40-year-old woman, 65 kg, 168 cm: 650 + 1,050 − 200 − 161 = 1,339 kcal/day.
Frequently asked questions
What's the difference between BMR and TDEE?
BMR is the calories you'd burn lying in bed all day. TDEE multiplies BMR by an activity factor (1.2–1.9) to capture daily movement, exercise and digestion.
Can I increase my BMR?
BMR is largely determined by body size and lean mass. Building muscle raises BMR modestly. Crash diets and rapid weight loss can lower it; gradual weight loss preserves more of it.
Is the Mifflin–St Jeor formula universal?
It's the most-recommended general-population formula. Athletes and very lean individuals may be better served by the Katch–McArdle equation, which uses lean body mass instead of total weight.