BMR Calculator

BMR is the energy your body uses at complete rest for vital functions such as breathing, circulation, and cell metabolism. Source: Academy of Nutrition and Dietetics.

The Mifflin-St Jeor equation (1990) is generally considered more accurate for the modern population than the older Harris-Benedict equation (1919). Both estimates typically fall within ±10 % of measured values.

BMR is your at-rest baseline. TDEE (Total Daily Energy Expenditure) adds physical activity, digestion (TEF), and non-exercise movement by multiplying BMR by an activity factor of 1.2–1.9.

Sex, age, height, weight, and especially lean muscle mass. Men typically have a 5–10 % higher BMR than women due to greater muscle mass.

Yes — from around age 30, BMR drops about 1–2 % per decade, mostly due to muscle loss (sarcopenia). Resistance training can substantially slow this decline.

Sustained intake below BMR is not recommended by major nutrition bodies because it risks metabolic adaptation, muscle loss, and nutrient deficiencies. Calorie deficits should be set against TDEE, not BMR.