BMR Calculator
Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation, widely considered the most accurate BMR formula.
About this Calculator
Calculate your Basal Metabolic Rate using the Mifflin-St Jeor equation, widely considered the most accurate BMR formula.
Formula & Calculations
Formula
Male: 10 × weight + 6.25 × height - 5 × age + 5 | Female: 10 × weight + 6.25 × height - 5 × age - 161Where:
- BMR=Basal Metabolic Rate — calories burned at complete rest (kcal/day)
- weight=Body mass in kilograms
- height=Body length in centimeters
- age=Age in years
Assumptions
- The Mifflin-St Jeor equation was validated in 1990 and is considered more accurate than the older Harris-Benedict equation.
- BMR represents calories needed for basic life functions (breathing, circulation, cell production) and does not include activity.
- Individual metabolism varies; BMR is an estimate, not a clinical measurement.
Calculation Examples
Example 1
10 × 80 + 6.25 × 180 - 5 × 30 + 5 = 800 + 1,125 - 150 + 5 = 1,780 kcal/day.
Example 2
10 × 60 + 6.25 × 165 - 5 × 25 - 161 = 600 + 1,031.25 - 125 - 161 = 1,345.25 kcal/day.
Frequently Asked Questions
What is the difference between BMR and TDEE?
BMR is the number of calories your body burns at complete rest to maintain vital functions. TDEE (Total Daily Energy Expenditure) includes BMR plus calories burned through physical activity and digestion. TDEE is always higher than BMR.
How do I use BMR for weight loss?
To lose weight, consume fewer calories than your TDEE (not your BMR). Never eat below your BMR for extended periods, as this can slow your metabolism. A moderate deficit of 300-500 calories below TDEE is generally recommended.
Which BMR formula is most accurate?
The Mifflin-St Jeor equation is considered the most accurate for the general population, with an error rate of about 10%. The older Harris-Benedict equation tends to overestimate BMR by about 5%.