BMR Calculator
Calories your body burns at rest.
Calories your body burns at rest.
Choose basal metabolism, daily energy needs, blood-glucose conversion or heart-rate zones.
Calories your body burns at rest.
Daily calories to maintain, lose or gain.
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Open calculatorYour Basal Metabolic Rate is the energy your body burns doing absolutely nothing — breathing, circulating blood, maintaining temperature, repairing cells. It typically accounts for 60–70% of everything you burn in a day, which makes it the foundation of any calorie plan.
The calculator uses the Mifflin-St Jeor equation, which validation studies have found the most accurate predictive formula for the general adult population, from your sex, age, height, and weight.
Weight in kg, height in cm, age in years; s = +5 for men and −161 for women. The output is calories per day at complete rest.
A 30-year-old man, 170 cm, 70 kg: BMR = 700 + 1,062.5 − 150 + 5 ≈ 1,618 calories per day — what his body burns before any movement at all.
This is a statistical estimate, not a medical measurement. Consult a professional before significant dietary changes.
BMR is the resting floor; TDEE (total daily energy expenditure) multiplies it by an activity factor to include movement and exercise. Diet targets should be set from TDEE, not BMR.
Meaningfully, mainly by adding muscle — muscle tissue burns more at rest than fat. Crash dieting does the opposite, suppressing BMR as the body adapts to scarcity.
Equations predict from population averages; individual metabolisms vary roughly ±10%. Lab tests (indirect calorimetry) measure your actual number, but for planning purposes the formula estimate is close enough for most people.
These sources are used to verify terminology, formulas, and information related to this calculator.