Weight Loss Time Calculator: Days to Reach Your Goal Weight
Enter your current weight, your goal weight and your daily calorie deficit to see how long it takes.
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Formula
Total deficit = (current − goal) × 7700 kcal
Days = total deficit ÷ daily deficit, rounded up.
Worked example
82 kg to 75 kg at a 600 kcal deficit: 7 × 7700 = 53,900 kcal; 53,900 ÷ 600 = 89.83, so 90 days, or 12.9 weeks.
Frequently asked questions
How is the time to reach my goal calculated?
Days = (current − goal) × 7700 ÷ daily deficit, rounded up. Going from 80 to 75 kg at 500 kcal a day takes 5 × 7700 ÷ 500 = 77 days.
Why 7700 kcal per kg?
A common rule of thumb says about 7700 kcal of energy is stored in 1 kg of body fat. It is an approximation, and real loss varies from person to person.
How big a daily deficit is reasonable?
Many guidelines suggest losing roughly 0.25 to 1 kg a week. A 500 kcal deficit is about 0.45 kg a week. Talk to a health professional before using a large deficit.
Will weight loss stay at this pace?
Usually not. As you lose weight your energy needs fall, so the same deficit slows down over time. Treat the result as an estimate and recheck as you go.