Basal Metabolic Rate (BMR) Calculator

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body requires at rest to maintain basic bodily functions like breathing, blood circulation, and cell repair.

How is BMR Calculated?

There are three widely used formulas for calculating BMR, each tailored to different needs:

• Mifflin-St Jeor Formula: The most commonly used method, offering accurate results for most individuals.

  BMR = (10 × weight in kg) + (6.25 × height in cm) - (5 × age in years) + 5 (male) or -161 (female)

  Example: A 24-year-old male, weighing 65 kg and 170 cm tall:

  BMR = (10 × 65) + (6.25 × 170) - (5 × 24) + 5 = 1655 kcal/day

• Revised Harris-Benedict Formula: A slightly older method, revised for improved accuracy.

  Male: BMR = 88.362 + (13.397 × weight in kg) + (4.799 × height in cm) - (5.677 × age in years)
  Female: BMR = 447.593 + (9.247 × weight in kg) + (3.098 × height in cm) - (4.330 × age in years)

  Example: A 30-year-old female, weighing 60 kg and 165 cm tall:

  BMR = 447.593 + (9.247 × 60) + (3.098 × 165) - (4.330 × 30) = 1429 kcal/day

• Katch-McArdle Formula: Ideal for individuals with access to body fat percentage measurements.

  BMR = 370 + (21.6 × Lean Body Mass in kg)
  LBM = Weight × (1 - Body Fat % as decimal)

  Example: A person weighing 70 kg with 20% body fat:

  LBM = 70 × (1 - 0.20) = 56 kg
  BMR = 370 + (21.6 × 56) = 1570 kcal/day

Activity Levels and Total Daily Energy Expenditure (TDEE)

To estimate your daily calorie needs, multiply your BMR by an activity factor:

• Sedentary: BMR × 1.2
• Lightly Active: BMR × 1.375
• Moderately Active: BMR × 1.55
• Very Active: BMR × 1.725
• Extra Active: BMR × 1.9