DocomintBMR Calculator
Calculate Basal Metabolic Rate — calories burned at rest — using the Mifflin-St Jeor formula.
BMR is the number of calories your body burns just staying alive at complete rest — breathing, circulation, cell repair — before any activity is added on top. This uses the Mifflin-St Jeor equation, generally considered more accurate for most people than the older Harris-Benedict formula it replaced.
Example: A 30-year-old man weighing 70kg at 175cm has a BMR of about 1,674 calories/day — see Calorie Calculator to multiply this by an activity factor for total daily calorie needs, since BMR alone assumes zero movement.
How it works
- Enter your gender, weight, height, and age
- Press Calculate BMR
- Your basal metabolic rate appears instantly, computed on your device using the Mifflin-St Jeor equation
Frequently asked questions
What's the difference between BMR and TDEE?
BMR is calories burned at complete rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor, accounting for movement and exercise — TDEE, not BMR, is your actual maintenance calorie level (see Calorie Calculator).
Why does gender affect BMR?
On average, men carry proportionally more muscle mass than women at the same weight, and muscle burns more calories at rest than fat tissue does — the Mifflin-St Jeor formula's gender-based offset (+5 for men, −161 for women) reflects that average difference.
Is my numbers uploaded anywhere?
No — BMR Calculator runs entirely in your browser using JavaScript/WebAssembly. Your numbers is never sent to a server.