How fast should weight loss be?
0.5-2 lbs weekly is safe. Faster often means water and muscle loss with rebound risk.
Health Fitness
Calorie Deficit Calculator
Calculate calorie deficit with your details.
Personalized estimate
Use realistic inputs for the most useful results.
What this calculator does
A calorie deficit calculator determines calories below maintenance for weight loss. 500 cal daily deficit creates ~1 lb/week loss. Sustainable deficits range 300-1,000 calories.
How it works
Calculate TDEE, then subtract deficit based on target weekly loss. 3,500 cal = 1 lb, 7,700 cal = 1 kg.
Formula
Target calories = TDEE - (weekly target × 3,500 ÷ 7). For 1 lb/week: TDEE - 500.
Tips for using this calculator
- Target 0.5-1 lb weekly for sustainable fat loss
- Combine deficit with strength training to preserve muscle
- Maintain high protein (0.8-1g per lb)
- Aggressive deficits (>1,000 cal) risk muscle loss
- Track weight weekly, expect 1-3 lb normal fluctuation
Frequently asked questions
Will I lose muscle in deficit?
Some loss is unavoidable. Minimize with high protein, strength training, and moderate deficit.
Why does weight loss slow?
Initial loss includes water weight. True fat loss is 0.5-2 lb/week. TDEE also decreases as you lose.