BMR Calculator

Estimate your Basal Metabolic Rate (BMR) — the calories your body burns at rest — using the Mifflin–St Jeor equation. Supports Imperial and Metric units.

BMR (Calories/day)
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About the BMR Calculator

The BMR Calculator estimates your Basal Metabolic Rate — the amount of energy your body needs each day to maintain essential functions such as breathing, blood circulation, nutrient processing, and cellular repair.

How the BMR Formula Works

CalculatorFox uses the Mifflin–St Jeor Equation, the modern gold-standard formula preferred by nutritionists because it is more accurate than older formulas like Harris–Benedict.

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

Example Calculation

BMR ≈ 1,688 calories/day

What Affects Your BMR?

  • Age, gender, muscle mass, genetics
  • Larger bodies burn more calories

BMR vs. TDEE

TDEE = BMR × Activity Level

How to Use BMR for Weight Goals

  • Weight Loss: Eat 10–20% below TDEE
  • Gain: Eat above TDEE
  • Maintain: Match TDEE

See also our Calorie Calculator.