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⚡ BMR Calculator

Calculate your Basal Metabolic Rate (BMR) — the number of calories your body burns at rest. Results are shown for both the Mifflin-St Jeor (more accurate) and classic Harris-Benedict formulas.

BMR Formulas

Mifflin-St Jeor (recommended)
Male: (10 × kg) + (6.25 × cm) − (5 × age) + 5
Female: (10 × kg) + (6.25 × cm) − (5 × age) − 161
Harris-Benedict (classic)
Male: 88.362 + (13.397 × kg) + (4.799 × cm) − (5.677 × age)
Female: 447.593 + (9.247 × kg) + (3.098 × cm) − (4.330 × age)
kg = weight in kg cm = height in cm age = age in years

How to Calculate Your BMR

  1. 1
    Choose Unit System
    Select Metric (kg/cm) or Imperial (lbs/ft) using the toggle.
  2. 2
    Enter Your Details
    Input your gender, age, height, and weight accurately.
  3. 3
    Click Calculate
    Both Mifflin-St Jeor and Harris-Benedict results appear instantly.
  4. 4
    Use the TDEE Table
    Multiply your BMR by your activity level to find your total daily calorie needs.

Example Calculation

Female, 30 years old, 165 cm, 65 kg:

Mifflin = (10 × 65) + (6.25 × 165) − (5 × 30) − 161
= 650 + 1031.25 − 150 − 161 = 1,370 kcal/day
Harris-Benedict = 447.593 + (9.247 × 65) + (3.098 × 165) − (4.330 × 30)
= 447.593 + 601.055 + 511.17 − 129.9 = 1,430 kcal/day
TDEE (moderately active × 1.55) ≈ 2,170 kcal/day

Frequently Asked Questions

Basal Metabolic Rate is the minimum number of calories your body needs to perform basic life-sustaining functions — breathing, circulation, cell production, and temperature regulation — while at complete rest. It accounts for roughly 60–70% of total daily energy expenditure.

Studies show the Mifflin-St Jeor equation (1990) is more accurate for most people, with an error margin of around 10%. The original Harris-Benedict formula (1919) tends to overestimate by 5–15%. The revised Harris-Benedict (1984) used here is more accurate than the original.

BMR is primarily determined by genetics, age, height, and muscle mass. Building lean muscle through resistance training is the most effective way to raise it, since muscle burns more calories at rest than fat. Eating adequate protein and avoiding very-low-calorie diets also helps preserve metabolic rate.

BMR is the calories burned at complete rest. TDEE (Total Daily Energy Expenditure) includes all calories burned through daily activities and exercise. TDEE = BMR × activity multiplier. If you eat at your TDEE, you maintain weight; below TDEE you lose weight; above TDEE you gain weight.

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