Health & Fitness

BMR Calculator

Calculate your Basal Metabolic Rate — the calories you burn at rest.

Enter your age, sex, height, and weight to calculate your Basal Metabolic Rate (BMR) using the Mifflin-St Jeor equation, the most widely used and accurate formula for estimating resting energy expenditure.

Enter a valid age.
kilograms (kg)Enter a valid weight.
centimetres (cm)Enter a valid height.

Your BMR

—

calories per day at complete rest

How to Use This Tool

  1. Select your unit system and sex.
  2. Enter your age, weight, and height.
  3. Click Calculate BMR to see your resting daily calorie burn.

The Mifflin-St Jeor Equation

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

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

What BMR Represents

Your Basal Metabolic Rate is the number of calories your body needs to maintain basic life functions — breathing, circulation, cell production — while completely at rest, with no physical activity or digestion factored in. It typically accounts for 60-75% of total daily calorie expenditure for most people.

Why Mifflin-St Jeor Over Other Formulas

The Mifflin-St Jeor equation, published in 1990, has been shown in multiple studies to be more accurate than the older Harris-Benedict equation (from 1919) for most modern populations, which is why it's now the standard formula recommended by the Academy of Nutrition and Dietetics.

From BMR to Total Calorie Needs

BMR alone doesn't tell you your total daily calorie needs — you need to multiply it by an activity factor to get your Total Daily Energy Expenditure (TDEE), which accounts for exercise and daily movement. Use our TDEE Calculator to take this next step.

Frequently Asked Questions

Is BMR the same as the calories I should eat per day?

No, BMR is only your resting calorie burn. Your actual daily calorie needs (TDEE) are higher and depend on your activity level — use a TDEE calculator for a complete estimate.

Why is BMR different for men and women?

The formula accounts for typical differences in body composition between sexes (men generally have more muscle mass, which burns more calories at rest), which is why the equation adds 5 for men and subtracts 161 for women.

This calculator is provided for general informational and estimation purposes only. Results should not be treated as professional financial, tax, legal, medical, or engineering advice. Always verify critical calculations with a qualified professional or official source before making decisions.