BMR Calculator

How to Calculate Your BMR

Your Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic functions at complete rest — breathing, circulation, cell production. It is the baseline for all calorie planning.

The Mifflin-St Jeor formula

Men: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age + 5

Women: BMR = 10×weight(kg) + 6.25×height(cm) − 5×age − 161

Step-by-step

1. Select your biological sex (the formula differs slightly).
2. Enter weight in kilograms, height in centimeters, and age.
3. The calculator shows your BMR plus daily needs at three activity levels.

Worked example

Male, 70 kg, 175 cm, age 30: BMR = 10×70 + 6.25×175 − 5×30 + 5 = 700 + 1093.75 − 150 + 5 = 1,649 cal/day. At moderate activity (×1.55): ~2,556 cal/day.

Activity multipliers

• Sedentary (desk job): BMR × 1.2
• Moderate (3–5 days exercise): BMR × 1.55
• Very active (6–7 days exercise): BMR × 1.725

To lose weight, eat below your TDEE (Total Daily Energy Expenditure). To gain, eat above it. A deficit of 500 cal/day typically leads to ~1 lb/week loss.