Calorie Deficit Calculator
Calculate the precise daily calorie deficit you need for your weekly weight-loss goal.
What is Calorie Deficit?
A calorie deficit is the only reliable lever for weight loss. The size of that deficit determines both the speed of progress and how easy it is to stick with the plan. Modest deficits (10–20% below maintenance) preserve muscle and energy; larger deficits speed results but raise risk of fatigue and rebound.
How is it calculated?
One kilogram of body fat stores roughly 7700 kcal. To lose 0.5 kg/week, eat 7700 × 0.5 / 7 ≈ 550 kcal below TDEE each day. Our calculator computes your TDEE (Mifflin-St Jeor × activity) and subtracts the deficit you select.
Frequently Asked Questions
- What is a safe deficit?
- 20–25% below TDEE is widely considered safe and sustainable.
- Why am I not losing despite the deficit?
- Track food precisely for two weeks; estimates often under-count calories by 20–30%.
- Will I lose muscle on a deficit?
- High protein (1.6–2.2 g/kg) and resistance training preserve most muscle.