BMR & TDEE Calculator
Resting metabolic rate and daily calorie needs by activity level.
An estimate. Individual metabolism varies substantially.
How it works
BMR is what your body burns doing nothing at all — breathing, circulation, keeping warm. It is typically 60-70% of total daily expenditure. TDEE multiplies BMR by an activity factor to estimate everything you burn in a day.
This uses the Mifflin-St Jeor equation, which outperforms the older Harris-Benedict formula in validation studies. Even so, individual variation runs to several hundred calories. Treat the number as a starting point, then adjust based on what actually happens to your weight over three or four weeks.
Common questions
Why do I need a deficit of 500 calories to lose 0.5 kg a week?
A kilogram of body fat stores roughly 7,700 calories, so half a kilo is about 3,850 — around 550 a day. In practice metabolism adapts downward as you lose weight, so the rate slows.
Should I eat below my BMR?
Generally not. Sustained intake below resting requirements is hard to maintain, costs muscle as well as fat, and is not something to attempt without medical supervision.