Calorie Deficit Calculator
Turn a weight goal into a daily calorie target, choose how fast you want to lose or gain and see the deficit (or surplus) and how long it will take. Calculates in your browser.
Daily calorie target
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Show the math
A weekly weight target becomes a daily calorie adjustment:
daily adjustment = rate/week × 7,700 ÷ 7
Roughly 7,700 kcal sits in a kilogram of fat (3,500 per pound), so losing 0.5 kg a week needs about a 550-calorie daily deficit. Keep deficits moderate, around 0.5–1% of body weight per week, to protect muscle and stay consistent.
What this does
A calorie deficit calculator turns a weight goal into a daily calorie target, you choose how fast to lose or gain and it shows the deficit (or surplus) and how long it will take.
How it works
Roughly 7,700 kcal is stored in a kilogram of body fat (about 3,500 per pound). The tool spreads your weekly target over seven days to find the daily calorie adjustment from your maintenance level.
How to use it
- Enter your maintenance calories (TDEE).
- Set your goal weight change and pace.
- Read the daily deficit or surplus.
- See the estimated time to reach your goal.
Understanding your result
A safe pace is about 0.25–1% of body weight per week, roughly a 500 kcal daily deficit. Larger deficits risk muscle loss and are hard to sustain; re-check maintenance every few weeks as metabolism adapts.
Example
Losing 0.5 kg a week needs about a 550 kcal daily deficit, for a 2,200 kcal maintenance, that is around 1,650 kcal a day.
Sources & methodology
- NIH, Body Weight Planner, How calorie change drives weight change
- USDA, Dietary Guidelines for Americans, Healthy calorie targets
Last updated .
Frequently asked questions
How big a deficit is safe?
A common guideline is 0.25–1% of body weight per week, often around 0.5 kg (1 lb). That maps to roughly a 500 kcal daily deficit. Larger deficits risk muscle loss and are hard to sustain.
Where does the 7,700 figure come from?
Roughly 7,700 kcal is stored in a kilogram of body fat (about 3,500 per pound). The tool spreads your weekly target over seven days to find the daily calorie adjustment.
Why is the estimate not exact?
Metabolism adapts as you lose weight and the 7,700 figure is an average, so real results vary. Re-check your maintenance calories every few weeks and adjust.
Do you keep my numbers?
No. Everything is calculated locally in your browser.
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