BMR Calculator

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Estimate your Basal Metabolic Rate — the calories your body burns at rest — using the accurate Mifflin-St Jeor equation. Metric or imperial, free and instant.

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kg
cm
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Your BMR – kcal / day
Per hour –
Your Basal Metabolic Rate is the energy your body uses at complete rest to keep vital functions running. It is calculated with the Mifflin-St Jeor equation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men or − 161 for women. Multiply your BMR by an activity factor to estimate your total daily calorie needs.

About BMR Calculator

The BMR Calculator estimates your Basal Metabolic Rate — the calories your body burns at complete rest just to keep vital functions like breathing, circulation and cell repair running. Enter your sex, age, height and weight in metric or imperial units to see your BMR per day and per hour.

It uses the Mifflin-St Jeor equation, widely regarded as the most accurate general formula: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age, plus 5 for men or minus 161 for women. Imperial inputs are converted automatically before the formula is applied.

BMR is the foundation of calorie planning: multiply it by an activity factor to estimate total daily needs, then eat below or above that to lose or gain weight. Knowing your resting burn helps you set realistic targets instead of guessing. Free and instant in your browser.

How to use BMR Calculator

  1. Select metric or imperial units.
  2. Choose your sex and enter your age.
  3. Enter your height and weight.
  4. Read your BMR in kcal per day, plus the per-hour figure.

Frequently asked questions

The Mifflin-St Jeor equation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5 for men, or − 161 for women. Studies show it predicts measured resting metabolism more closely than the older Harris-Benedict formula.

Most adults fall roughly between 1,200 and 2,000 kcal per day. Larger, younger and taller people burn more at rest, and men typically have higher BMRs than women of the same size because of greater lean mass.

BMR is your burn at complete rest; TDEE (Total Daily Energy Expenditure) adds movement and exercise by multiplying BMR by an activity factor between about 1.2 and 1.9. Use TDEE to plan calories, BMR as the base.

Sustained intakes below BMR are aggressive and can be counterproductive, since your actual daily burn (TDEE) is higher than BMR. Moderate deficits of around 250–500 kcal below TDEE are the usual recommendation.

It is a general estimate, not medical advice. Formulas cannot see your muscle mass, genetics or health conditions, and individual metabolisms vary by ±10% or more — consult a professional for personalized guidance.
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