How Long to Lose 20 Pounds with a 500-Calorie Deficit?
Losing 20 pounds with a 500-calorie daily deficit takes approximately 20 weeks.
How to use this tool
- Enter current weight, goal weight and daily calorie deficit in the fields above.
- Results update instantly as you type — or click Calculate.
- Read your weeks to goal and the full breakdown beneath it.
A 500-calorie daily deficit is the classic approach for safe, steady weight loss — see exactly how many weeks it takes to drop 20 pounds.
Frequently asked questions
- Why 3,500 calories per pound?
- The 3,500 kcal/lb rule is a widely used approximation. Actual results vary with age, sex, body composition and metabolic adaptation.
- Is 500 kcal/day a safe deficit?
- A 500 kcal/day deficit targets ~1 lb/week loss and is generally considered safe for most adults, but consult your doctor if you have health conditions.