Calculate your Basal Metabolic Rate — the number of calories your body needs at complete rest.
A BMR calculator determines your Basal Metabolic Rate — the number of calories your body burns at complete rest to maintain vital functions like breathing, circulation, and cell production.
Example: A 30-year-old male, 70 kg, 175 cm has a BMR of 1,693 calories/day. BMR accounts for 60-75% of total daily calorie burn.
| Activity Level | Multiplier | Description |
|---|---|---|
| Sedentary | 1.2 | Little or no exercise |
| Lightly Active | 1.375 | Light exercise 1–3 days/week |
| Moderately Active | 1.55 | Moderate exercise 3–5 days/week |
| Very Active | 1.725 | Hard exercise 6–7 days/week |
| Extra Active | 1.9 | Very hard exercise + physical job |
BMR is the number of calories your body needs to maintain basic life functions (breathing, circulation, cell production) while at complete rest. It accounts for 60-75% of your total daily calorie expenditure.
The Mifflin-St Jeor equation is the most accurate formula for estimating BMR. For men: BMR = 10xweight(kg) + 6.25xheight(cm) - 5xage + 5. For women: BMR = 10xweight(kg) + 6.25xheight(cm) - 5xage - 161.
First, calculate your TDEE by multiplying BMR by your activity level. To lose weight, eat 300-500 calories below your TDEE. Never eat below your BMR for extended periods, as this can slow metabolism and cause nutrient deficiencies.
Yes, BMR decreases approximately 1-2% per decade after age 20, primarily due to loss of muscle mass. Regular strength training and adequate protein intake can help maintain a higher BMR as you age.