BMR Calculator
Enter your details to estimate your Basal Metabolic Rate — the calories your body burns at rest.
How this calculator works
Basal Metabolic Rate (BMR) is the number of calories your body needs to maintain basic functions — breathing, circulation, cell production — while completely at rest. This calculator shows two widely used formulas side by side: the Mifflin-St Jeor equation, generally considered more accurate for the modern population, and the older Harris-Benedict equation (revised 1984 version), still commonly used as a reference. For a closer look at how the two formulas compare, see our full guide to BMR formulas.
The formulas
Mifflin-St Jeor (men): 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
Mifflin-St Jeor (women): 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Harris-Benedict (men): 88.362 + 13.397 × weight(kg) + 4.799 × height(cm) − 5.677 × age
Harris-Benedict (women): 447.593 + 9.247 × weight(kg) + 3.098 × height(cm) − 4.330 × age
Frequently asked questions
Is BMR the same as the calories I should eat?
No — BMR only covers the energy your body burns at complete rest. Your actual daily calorie needs (TDEE) are higher once you factor in movement, exercise, and digestion. Use our Calorie Calculator to estimate that full picture.
Why do the two formulas give different results?
Mifflin-St Jeor and Harris-Benedict were derived from different study populations decades apart. Mifflin-St Jeor (1990) is generally regarded as more accurate for today's population, while Harris-Benedict (revised 1984) tends to run slightly higher. The gap between them is usually small — under 5%.