BMR Calculator
Calculate your Basal Metabolic Rate and daily calorie needs by activity level.
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BMR Calculator
Use the formula and worked example below to calculate manually.
Overview
BMR (Basal Metabolic Rate) is the number of calories your body burns at complete rest to maintain vital functions. Multiply by your activity factor to get your TDEE — Total Daily Energy Expenditure — the calories needed to maintain your current weight.
How to use this calculator
- Enter your age, gender, height, and weight.
- Select your activity level.
- The calculator shows your BMR and TDEE.
- Adjust by ±500 calories to lose or gain 0.5 kg per week.
Understanding the inputs & results
BMR
Basal Metabolic Rate — calories burned at complete rest for basic physiological functions (breathing, circulation, cell repair).
TDEE
Total Daily Energy Expenditure — BMR × activity multiplier. Your total caloric need for the day.
Activity multiplier
Factor applied to BMR based on how active you are: 1.2 (sedentary) to 1.9 (very active).
Caloric deficit
Eating fewer calories than TDEE to lose weight. A 500 cal/day deficit ≈ 0.5 kg/week loss.
Caloric surplus
Eating more than TDEE to gain weight or muscle. A 300–500 cal surplus per day is typical for lean bulking.
The formula
Mifflin-St Jeor equation (most accurate)
Men: BMR = 10W + 6.25H − 5A + 5 | Women: BMR = 10W + 6.25H − 5A − 161
W = weight (kg), H = height (cm), A = age (years). TDEE = BMR × activity factor (1.2–1.9).
Worked example
Male, 30 years, 75 kg, 175 cm, moderately active.
- BMR = 10×75 + 6.25×175 − 5×30 + 5 = 750 + 1093.75 − 150 + 5 = 1698.75 ≈ 1,699 cal.
- TDEE = 1,699 × 1.55 (moderately active) ≈ 2,633 cal/day.
✓ BMR ≈ 1,699 calories. TDEE ≈ 2,633 calories/day to maintain current weight.
Frequently asked questions
Calorie calculations are estimates. Individual metabolism varies. Consult a nutritionist or doctor before making significant dietary changes.