BMR Calculator

The 166-calorie gap between two otherwise identical people

Run 80 kg, 180 cm, 30 years old, male through this calculator and the base arithmetic — (10 × 80) + (6.25 × 180) − (5 × 30) = 1775 — plus 5 for the sex term gives a BMR of 1,780 kcal/day. Swap only the sex to female, same weight, height and age, and the formula subtracts 161 instead of adding 5: 1775 − 161 = 1,614 kcal/day. That 166-calorie gap comes entirely from one term in the equation, reflecting average body-composition differences between men and women at an identical height, weight and age — nothing else in the calculation changed.

An equation from 1990 that's still the reference standard

This calculator uses the Mifflin-St Jeor equation, published in 1990 and still regarded as the most accurate BMR formula for healthy adults among the several in wide use. The full calculation: 10 × weight(kg) + 6.25 × height(cm) − 5 × age, then +5 for males or −161 for females. BMR itself is the energy your body burns just to stay alive at complete rest — before any walking, working or deliberate exercise enters the picture — which makes it the floor every other calorie calculation builds on top of.

Why this number alone isn't a diet plan

BMR tells you the minimum your body needs to keep vital functions running at rest; it was never meant to be eaten *at*, and doing so for extended periods tends to backfire rather than help sustainable weight management. The useful next step is multiplying this figure by an activity factor to get TDEE (Total Daily Energy Expenditure) — your actual maintenance calories including movement — which the calorie calculator on this site does automatically, then layers a goal-based deficit or surplus on top. Treat this BMR figure as the foundation any weight plan gets built on, not the target itself.

This is a general estimate, not medical advice. Consult a doctor or registered dietitian for personalised guidance.