BMR Calculator

BMR (Basal Metabolic Rate) is the minimum number of calories your body requires to sustain essential life functions · breathing, blood circulation, body temperature regulation, cell growth and repair · while at complete rest in a thermally neutral environment and in a post-absorptive state (after not eating for at least 12 hours). It typically accounts for 60-75% of total daily calorie expenditure.

The most commonly used formulas are the Mifflin-St Jeor equation and the Harris-Benedict equation. The Mifflin-St Jeor formula for men is: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5. For women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161. These equations account for weight, height, age, and sex.

BMR is influenced by several factors: age (BMR decreases roughly 2% per decade after 20), sex (men generally have higher BMR due to greater muscle mass), body composition (muscle tissue burns more calories at rest than fat), genetics, thyroid hormone levels, pregnancy, and environmental temperature. Certain medical conditions like hypothyroidism can significantly lower BMR.

Yes, to a meaningful extent. The most effective way to increase BMR is to build lean muscle mass through resistance training, since muscle is metabolically more active than fat. Eating adequate protein also has a higher thermic effect and helps preserve muscle. Avoiding very-low-calorie diets is important because severe caloric restriction causes adaptive metabolic suppression that lowers BMR. Consistent sleep and stress management also support a healthy metabolic rate.