Enter your sex, age, height, weight and activity level to estimate your resting metabolic rate (RMR), your total daily energy expenditure (TDEE), and simple calorie targets for losing or gaining weight. It is a starting point for diet and fitness planning, not medical advice.
How it works
The calculator uses the Mifflin-St Jeor equation, the most validated predictive formula for resting metabolism. With weight in kg, height in cm, and age in years:
- Men: RMR = 10 × kg + 6.25 × cm − 5 × age + 5
- Women: RMR = 10 × kg + 6.25 × cm − 5 × age − 161
It then multiplies RMR by an activity factor (1.2 sedentary to 1.9 very active) to get TDEE, the calories needed to maintain your weight. Finally it offers calorie targets by adjusting TDEE by ±250 kcal/day for a gentle ~0.25 kg per week change.
Example
A 30-year-old man, 80 kg, 180 cm, moderately active:
- RMR = 10 × 80 + 6.25 × 180 − 5 × 30 + 5 = 800 + 1,125 − 150 + 5 = 1,780 kcal/day
- TDEE = 1,780 × 1.55 ≈ 2,759 kcal/day
- Mild loss = 2,759 − 250 ≈ 2,509 kcal/day
- Mild gain = 2,759 + 250 ≈ 3,009 kcal/day
| Activity level | Multiplier |
|---|---|
| Sedentary | 1.2 |
| Light | 1.375 |
| Moderate | 1.55 |
| Active | 1.725 |
| Very active | 1.9 |
Everything is calculated privately in your browser; actual metabolism varies with body composition and genetics.