How the number is worked out
Your resting burn (BMR) comes from the Mifflin-St Jeor equation, the one most dietitians use. It is multiplied by an activity factor to get your maintenance calories, and each goal then adds or removes the deficit for that rate of change — about 7,700 kcal per kilogram.
Women: 10 × kg + 6.25 × cm − 5 × age − 161
| Activity | Multiplier |
|---|---|
| Sedentary | × 1.2 |
| Light | × 1.375 |
| Moderate | × 1.55 |
| Very active | × 1.725 |
| Extra active | × 1.9 |
Common questions
Why 7,700 calories per kilogram?
That's the widely used estimate for a kilogram of body fat's energy content. It's an approximation — real weight change also includes water and some lean tissue, especially early in a diet — but it's the standard rule of thumb calorie calculators use.
Does this use my exact BMR formula or an average?
It uses Mifflin-St Jeor specifically — the formula most dietitians consider the most accurate for the general population. If you want to compare it against Harris-Benedict or Katch-McArdle, the BMR calculator lets you pick.
Why might I not lose weight even eating the suggested deficit?
The deficit assumes your TDEE estimate is accurate, which it usually is within about 10% — everyday activity, sleep and stress all shift real energy use around. If a few weeks show no change, treat the actual scale trend as the correction, not the formula.
For general information only — not medical advice. Talk to a doctor about anything that concerns you.