BMR Calculator

Basal Metabolic Rate

Calculate the number of calories your body burns at complete rest to maintain basic functions like breathing and circulation.

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Understanding BMR

What is BMR?

Basal Metabolic Rate (BMR) is the number of calories your body needs to perform basic life-sustaining functions. These include breathing, circulation, nutrient processing, and cell production. Think of it as the energy cost of simply being alive.

The Mifflin-St Jeor Formula

We use the Mifflin-St Jeor equation, developed in 1990 and widely considered the most accurate BMR formula for modern populations.

Male: BMR = (10 × weightkg) + (6.25 × heightcm) - (5 × age) + 5
Female: BMR = (10 × weightkg) + (6.25 × heightcm) - (5 × age) - 161

Factors That Affect BMR

  • •Muscle mass: More muscle means higher BMR—muscle burns more calories than fat at rest
  • •Age: BMR typically decreases 1-2% per decade after age 20
  • •Sex: Men generally have higher BMR due to greater muscle mass
  • •Genetics: Some people naturally have faster or slower metabolisms
  • •Hormones: Thyroid function significantly impacts metabolic rate

BMR vs TDEE

Your BMR is just the baseline—it doesn't account for any physical activity. Your Total Daily Energy Expenditure (TDEE) includes BMR plus the calories burned through daily activities, exercise, and digestion. TDEE is typically 1.2x to 1.9x your BMR depending on how active you are.