Basal Metabolic Rate (BMR) Calculator
Calculate the calories your body burns at rest and your total daily energy needs based on your activity level.
This tool is for informational purposes only. Consult a dietitian or doctor for personal diet or health programmes. Calculation formulas are based on average populations; individual variation may cause ±15% deviation.
How Is BMR Calculated? Harris-Benedict Formula
Basal Metabolic Rate (BMR) is the minimum amount of energy your body needs while at complete rest — to sustain vital functions like digestion, breathing, and cell renewal. The calculation uses age, gender, height, and weight variables. Two separate formulas are applied since men and women have different muscle-to-fat ratios. Our tool uses the globally recognized Harris-Benedict and Mifflin-St Jeor equations to provide the most accurate result.
Factors That Affect Metabolism
As muscle mass increases, basal metabolic rate increases too, because muscle cells burn more energy at rest than fat cells. As age advances, BMR generally decreases. Genetic factors, hormonal status (thyroid, etc.) and body temperature also affect energy expenditure.
Calculation Formulas
| Formula | Equation | Year |
|---|---|---|
| Mifflin-St Jeor (Male) | 10 × weight + 6.25 × height − 5 × age + 5 | 1990 |
| Mifflin-St Jeor (Female) | 10 × weight + 6.25 × height − 5 × age − 161 | 1990 |
| Harris-Benedict (Male) | 13.397 × weight + 4.799 × height − 5.677 × age + 88.36 | 1984 |
| Harris-Benedict (Female) | 9.247 × weight + 3.098 × height − 4.330 × age + 447.59 | 1984 |
* Height in cm, weight in kg. Mifflin-St Jeor is currently considered the most accurate method.
How Should You Use Your BMR Value?
If you want to lose weight, your total calorie intake should not fall below your BMR value (extreme calorie restriction slows metabolism). The ideal approach is to find your Total Daily Energy Expenditure (TDEE) by multiplying your BMR by an activity multiplier, then create a 15-20% deficit from that value.
Activity Multipliers (TDEE)
Sedentary
Desk job, no daily exercise
Lightly Active
Light exercise 1–3 days/week
Moderately Active
Moderate exercise 3–5 days/week
Very Active
Hard training 6–7 days/week
Extra Active
Physical job + daily intense training