nutrition
Bmr calculator
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to keep your heart beating, lungs breathing, and organs functioning. It accounts for roughly 60–75% of total daily calorie expenditure for most people.
How to use this calculator
- Enter your weight, height, age, and biological sex.
- Optionally enter your body fat percentage to unlock the Katch-McArdle formula.
- Click Calculate BMR to compare results across all formulas.
- Use the Mifflin-St Jeor result as the default — it is the most validated formula for the general population.
The formulas
Mifflin-St Jeor (recommended)
Male: 10 × kg + 6.25 × cm − 5 × age + 5
Female: 10 × kg + 6.25 × cm − 5 × age − 161
Harris-Benedict (1984 revised)
Male: 13.397 × kg + 4.799 × cm − 5.677 × age + 88.362
Female: 9.247 × kg + 3.098 × cm − 4.330 × age + 447.593
Katch-McArdle (requires body fat %)
BMR = 370 + 21.6 × lean body mass (kg)
How to interpret your result
The three formulas typically differ by 50–150 kcal/day. If you know your body fat percentage, Katch-McArdle tends to be the most accurate because it accounts for lean mass directly. Multiply your BMR by your activity factor to get your TDEE.
Related tools
- TDEE Calculator — multiply BMR by an activity factor
- Macro Calculator — set protein, fat, and carb targets from your TDEE
Read more
What is BMR?
Basal Metabolic Rate (BMR) is the number of calories your body burns at complete rest — just to keep your heart beating, lungs breathing, and organs functioning. It accounts for roughly 60–75% of total daily calorie expenditure for most people.
How to use this calculator
- Enter your weight, height, age, and biological sex.
- Optionally enter your body fat percentage to unlock the Katch-McArdle formula.
- Click Calculate BMR to compare results across all formulas.
- Use the Mifflin-St Jeor result as the default — it is the most validated formula for the general population.
The formulas
Mifflin-St Jeor (recommended)
Male: 10 × kg + 6.25 × cm − 5 × age + 5
Female: 10 × kg + 6.25 × cm − 5 × age − 161
Harris-Benedict (1984 revised)
Male: 13.397 × kg + 4.799 × cm − 5.677 × age + 88.362
Female: 9.247 × kg + 3.098 × cm − 4.330 × age + 447.593
Katch-McArdle (requires body fat %)
BMR = 370 + 21.6 × lean body mass (kg)
How to interpret your result
The three formulas typically differ by 50–150 kcal/day. If you know your body fat percentage, Katch-McArdle tends to be the most accurate because it accounts for lean mass directly. Multiply your BMR by your activity factor to get your TDEE.
Related tools
- TDEE Calculator — multiply BMR by an activity factor
- Macro Calculator — set protein, fat, and carb targets from your TDEE
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