Basal Metabolic Rate (BMR) Calculator
Calculate the calories your body burns at rest and your total daily energy needs based on your activity level.
Your Body Burns Calories Even at Complete Rest
Breathing, heartbeat, body temperature, cell repair — all of these require energy. Even lying completely still, your body uses a set number of calories every day to keep these vital functions running. This value is called your Basal Metabolic Rate (BMR). Knowing this baseline number is essential for building a proper diet plan, losing weight or gaining muscle.
What Is BMR?
Basal Metabolic Rate is the minimum number of calories the body expends at complete rest (lying down, fasting, in a neutral temperature). It accounts for approximately 60–75% of total daily calorie needs and varies significantly from person to person based on age, sex, height and weight.
How to Use This Tool
Required Inputs
- Height (cm); your barefoot height measurement
- Weight (kg); weight measured in the morning before eating
- Age; your exact age
- Sex: hormonal differences affect BMR
What Do the Results Mean?
The tool calculates BMR using two formulas: Mifflin-St Jeor (modern standard) and Harris-Benedict (historical reference). It then lists TDEE (Total Daily Energy Expenditure) values for 5 different lifestyles using activity multipliers.
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.
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.
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
How Should I Set My Calorie Goals?
Your TDEE is the daily calorie amount needed to maintain your current weight. General recommendations suggest a deficit of 300–500 kcal/day to lose weight and a surplus of 200–400 kcal to gain muscle. Deficits exceeding 1,000 kcal/day can lead to muscle loss, hormonal imbalance and metabolic slowdown.
Tips for Accurate Results
- Weigh yourself in the morning after using the bathroom and before eating; this gives the most consistent reading.
- Choose your activity level honestly; most people overestimate their activity and end up consuming too many calories.
- BMR declines with age; expect roughly a 2–3% decrease per decade, especially after 30.
- The calculated TDEE is a starting point. Track your weight for 2–3 weeks; if change differs from expectations, adjust calories in small increments.