Calorie Deficit Calculator

First the calculator estimates your maintenance calories (TDEE) from the Mifflin-St Jeor equation and your activity level. Roughly 7,700 kcal equals a kilogram of body mass, so losing 0.5 kg a week needs a deficit of about 0.5 × 7,700 ÷ 7 ≈ 550 kcal per day. Your target is maintenance minus that deficit.

A deficit of 0.5 to 1% of body weight per week is the usual sweet spot — fast enough to see progress, slow enough to keep muscle and stay sane. Bigger deficits are not better: they cost lean mass, tank energy and rarely last. If the target drops below roughly 1,200–1,500 kcal, choose a gentler rate.

These are estimates — hold the target for two to three weeks and watch the trend on the scale, not day-to-day noise. If nothing moves, your maintenance or your logging is off by a little; trim another 100–200 kcal or tighten tracking rather than crashing lower.