Weight Loss Calculator
Calculate how long it will take to reach your target weight based on a daily calorie deficit.
Weight Loss Calculator
Calculate how long it will take to reach your target weight based on a daily calorie deficit.
Calories below your TDEE each day
Real-World Examples
180 → 160 lbs, 500 cal/day deficit
20 weeks (1 lb/week)
200 → 170 lbs, 1000 cal/day deficit
15 weeks (2 lbs/week)
160 → 150 lbs, 250 cal/day deficit
20 weeks (0.5 lb/week)
Common Mistakes to Avoid
Assuming the deficit stays constant
Fix: As you lose weight, your TDEE decreases because a smaller body burns fewer calories. A 500 cal deficit at 200 lbs may be only 300 at 180 lbs. Recalculate your TDEE and deficit every few weeks.
Aiming for very fast weight loss
Fix: Losing more than 2 lbs/week increases muscle loss, gallstone risk, and rebound weight gain. A moderate deficit preserves muscle and is far more sustainable long-term.
Forgetting the 3500 cal/lb rule is an estimate
Fix: The 3500 cal/lb rule is an approximation. Real weight loss is non-linear due to water, glycogen, and metabolic adaptation. Track actual weight over time and adjust the deficit based on results.