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BMR Calculator

Calculate your Basal Metabolic Rate (BMR) and daily calorie requirements based on your activity level.

How to Use

  1. 1

    Select your unit system: Metric (kg, cm) or Imperial (lbs, inches)

  2. 2

    Choose your biological sex

  3. 3

    Select your preferred BMR equation (Mifflin-St Jeor is recommended)

  4. 4

    Enter your weight, height, and age

  5. 5

    View your BMR and daily calorie needs based on activity level

Examples

Good Examples

Average adult male (metric, Mifflin-St Jeor)

(10 × 70) + (6.25 × 170) - (5 × 30) + 5 = 1,680 calories/day

Active female daily needs

BMR 1,400 × 1.55 (moderate activity) = 2,170 calories/day

Bad Examples

Using BMR as total daily calories

BMR is only the minimum at rest — actual needs are higher based on activity

Mixing metric and imperial

Entering weight in kg but height in inches gives meaningless results

Common Mistakes

  • Confusing BMR with total daily calorie needs — BMR is the minimum at rest; multiply by activity factor for actual needs
  • Not accounting for body composition — BMR formulas don't distinguish between muscle and fat mass
  • Using the wrong equation — different equations may give different results; Mifflin-St Jeor is considered most accurate for most people
  • Forgetting age factor — BMR decreases with age, so recalculate periodically
  • Mixing unit systems — use either metric (kg, cm) or imperial (lbs, inches), not a mix

Frequently Asked Questions

Q

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions at rest, such as breathing, circulation, and cell production. It typically accounts for 60-75% of your total daily calorie expenditure.

Q

What is the difference between BMR and TDEE?

BMR is the calories you burn at complete rest. TDEE (Total Daily Energy Expenditure) is BMR multiplied by an activity factor, representing your actual daily calorie needs. TDEE ranges from 1.2x BMR (sedentary) to 1.9x BMR (super active).

Q

Which BMR formula is most accurate?

The Mifflin-St Jeor equation is considered the most accurate for most people. The original Harris-Benedict equation tends to overestimate BMR. The Harris-Benedict revised equation is a 1984 update that is closer to Mifflin-St Jeor.

Q

Does muscle mass affect BMR?

Yes — muscle tissue burns more calories at rest than fat tissue. This is why athletes and people with higher muscle mass tend to have a higher BMR, even at the same weight. The standard BMR formulas do not account for body composition directly.