Calorie Deficit Calculator
Find a safe daily calorie deficit for your weight-loss goal, and see the predicted weekly weight loss and time to reach your target weight.
Maintenance calories use the Mifflin-St Jeor equation with an activity multiplier. The deficit (or surplus) assumes roughly 7,700 kcal per kilogram of body mass, spread across seven days. That constant is an approximation: early weight change often includes water, and metabolic rate falls as you lose weight, so real progress usually slows over time.
Frequently asked questions
What is a safe calorie deficit?
A deficit of roughly 500 kcal a day is a common, sustainable target, which works out at about 0.5 kg of weight loss a week. Larger deficits lose weight faster but are harder to stick to and risk losing muscle.
How many calories do I need to lose weight?
Take your TDEE and subtract the deficit. This calculator does it from your height, weight, age and activity level, and warns you if the target would drop below the minimum considered safe for your sex.
Why has my weight loss stopped?
As you lose weight your TDEE falls — a smaller body burns fewer calories — so the deficit that worked at first becomes maintenance. Recalculate your numbers and adjust, rather than cutting calories indefinitely.
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