BMR Calculator (Basal Metabolic Rate)

BMR is the number of calories your body needs to maintain basic life-sustaining functions — like breathing, circulation, cell production, and maintaining body temperature — while at complete rest. It represents roughly 60–70% of your total daily calorie expenditure. See also our Calorie Calculator.

Your BMR is primarily influenced by age, sex, weight, and height. Men generally have a higher BMR than women due to greater muscle mass. BMR also decreases with age as muscle mass typically declines. Other factors include genetics, hormonal levels (especially thyroid hormones), body composition, and environmental temperature.

For most adults, BMR ranges from about 1,200 to 2,400 calories per day. Women typically fall between 1,200–1,600 Cal/day, while men typically range from 1,600–2,400 Cal/day. These are resting values — your actual daily calorie needs will be higher depending on your activity level.

This calculator uses the Mifflin-St Jeor equation, widely regarded as the most accurate BMR formula. For men: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) + 5. For women: BMR = (10 × weight in kg) + (6.25 × height in cm) − (5 × age) − 161. Enter your details above to get your result automatically. You might also find our find Your BMR (Katch-McArdle) with Katch-McArdle Calculator useful.

BMR is your calorie need at complete rest — it's the baseline. TDEE (Total Daily Energy Expenditure) multiplies your BMR by an activity factor to estimate how many calories you actually burn each day based on your lifestyle. TDEE is what you should use to set daily calorie targets for weight management.

The most effective way to raise your BMR is to build lean muscle mass through strength training, since muscle tissue burns more calories at rest than fat. Eating enough protein, avoiding prolonged very-low-calorie diets (which can suppress metabolism), staying hydrated, and getting adequate sleep also support a healthy metabolic rate.

They are very similar but not identical. BMR is measured under strict conditions — complete rest, fasted state, and a thermoneutral environment. RMR is measured under less rigid conditions and is slightly higher (by about 10–20%) than true BMR. In everyday use, the terms are often used interchangeably.

The Mifflin-St Jeor equation is considered the most accurate BMR prediction formula for most people, with studies showing it estimates resting metabolic rate within about 10% for roughly 80% of individuals. It is less accurate for very muscular athletes or individuals with very high body fat percentages, where body composition-based formulas (like Katch-McArdle) may perform better.