BMR Calculator

Calculate your Basal Metabolic Rate (BMR) - the number of calories your body needs at complete rest.

ft
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Required for the Katch-McArdle formula only.
BMR Calculation Results
Your Basal Metabolic Rate (BMR)

0 calories/day

This is the number of calories your body needs at complete rest.

Daily Calorie Needs Based on Activity Level
Activity Level Description Calories
Sedentary Little or no exercise 0
Light Activity Light exercise/sports 1-3 days/week 0
Moderate Activity Moderate exercise/sports 3-5 days/week 0
Very Active Hard exercise/sports 6-7 days/week 0
Extra Active Very hard exercise/physical job/training twice a day 0
Comparison of Different Formulas
Formula BMR (calories/day) Best For
Mifflin-St Jeor 0 Most accurate for the general population
Harris-Benedict 0 Traditional formula, slightly overestimates
Katch-McArdle 0 Best for those who know their body fat percentage
Visualization
BMR by Formula
Daily Calorie Needs by Activity Level
About BMR

Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic physiological functions while at complete rest. These functions include:

  • Breathing
  • Blood circulation
  • Cell production
  • Nutrient processing
  • Protein synthesis
BMR Accounts For:
  • 60-70% of your total daily energy expenditure
  • Varies based on age, gender, weight, height, and body composition
  • Decreases with age (typically 1-2% per decade after age 20)
Note: BMR is different from Total Daily Energy Expenditure (TDEE), which includes physical activity and the thermic effect of food.
BMR Formulas Explained
Mifflin-St Jeor Formula (1990)

For men: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5

For women: BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) - 161

Most accurate for the general population according to research.

Harris-Benedict Formula (Revised 1984)

For men: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) - (5.677 × age in years)

For women: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) - (4.330 × age in years)

Traditional formula, tends to slightly overestimate BMR.

Katch-McArdle Formula (1974)

BMR = 370 + (21.6 × Lean Body Mass in kg)

Where Lean Body Mass = Weight in kg × (1 - Body Fat % / 100)

Most accurate for those who know their body fat percentage.

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