BMR Calculator
Enter your details to see your basal metabolic rate.
Basal metabolic rate is the energy your body needs at complete rest to maintain vital functions. The Mifflin St Jeor equation is one of the more accurate simple formulas for adults. Provide sex, weight in kilograms, height in centimetres, and age in years. The result is in kilocalories per day. Everything is computed locally.
How to use
- Select male or female.
- Enter weight in kilograms, height in centimetres, and age in years.
- Read the estimated BMR in kilocalories per day.
- Use the number as a starting point for maintenance calorie planning (multiply by an activity factor for real life).
Examples
- Male, 80 kg, 180 cm, 35 years: BMR about 1,755 kcal per day.
- Female, 60 kg, 165 cm, 28 years: BMR about 1,330 kcal per day.
- A 0.1 kg change in weight moves BMR by roughly 1 kcal for most adults.
FAQs
- What is the Mifflin St Jeor formula?
- For men: 10 times weight in kg plus 6.25 times height in cm minus 5 times age plus 5. For women the constant at the end is minus 161 instead of plus 5. The tool uses exactly these coefficients.
- Is BMR the same as maintenance calories?
- No. BMR is calories at complete rest. To estimate maintenance (TDEE) multiply BMR by an activity factor, typically 1.2 for sedentary up to 1.9 for very active lifestyles. See the calorie calculator for that step.
- How accurate is this estimate?
- Mifflin St Jeor is among the better validated simple equations for healthy adults, but individual metabolism varies with muscle mass, hormones, illness, and other factors. Treat the number as a useful starting estimate.
- Does it work for athletes or older adults?
- The formula was derived from a broad adult sample. Very muscular or very elderly individuals may find the result less representative. Adjust expectations and consider professional measurement when precision matters.
- Is any data uploaded?
- No. The arithmetic runs in your browser with no network calls. Your inputs stay on your device.
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