Calorie Deficit Calculator
Tell us how much you would like to lose each week and we show the daily deficit and the calories to aim for.
This calculator gives general estimates for information only. It is not medical advice and does not replace a consultation with a doctor or other qualified health professional.
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The formula
Daily deficit = (kg per week x 7,700) / 7. Target calories = maintenance - daily deficit.
How a calorie deficit works
To lose a kilogram of body fat you need to burn about 7,700 more calories than you eat. Spread over a week, losing half a kilo means a deficit of roughly 550 calories a day.
What is a safe pace?
Most guidance points to 0.25 to 1 kilo a week, and no more than about 1 percent of your body weight. Faster loss tends to cost muscle and is harder to sustain. If the plan would put you under 1,200 (women) or 1,500 (men) calories, we show a warning.
Make the deficit easier
- Walk more. It adds to your burn without the hunger of eating less.
- Keep protein high to protect muscle.
- Weigh yourself weekly, not daily, because water makes the scale jump around.
Examples to check
Type these into the calculator above to see how it behaves. Every result below was produced by the same calculator code that runs on this page.
| What you enter | What you get |
|---|---|
| Male; Age (years): 30; Height (cm): 180; Weight (kg): 80; Moderate (3-5 days a week); Weight to lose per week (kg): 0.5 | Daily calories to hit your goal: 2,209 kcal/day |
| Female; Age (years): 30; Height (cm): 165; Weight (kg): 65; Light (exercise 1-3 days a week); Weight to lose per week (kg): 0.5 | Daily calories to hit your goal: 1,334 kcal/day |
| Female; Age (years): 40; Height (cm): 160; Weight (kg): 72; Sedentary (little or no exercise); Weight to lose per week (kg): 0.5 | Daily calories to hit your goal: 1,081 kcal/day |
Calorie Deficit Calculator: frequently asked questions
How accurate are calorie calculators?
They are estimates, usually within about 10 percent. Your real needs depend on genetics, muscle, sleep and how much you move outside of exercise. Track your weight for two to three weeks and adjust by 100 to 200 calories if it is not moving as expected.
How many calories is a pound of fat?
About 3,500 calories per pound, or 7,700 per kilogram. This is a handy rule of thumb, but real weight loss slows down over time as your body adapts.
Can I rely on this result as medical advice?
No. It is a general estimate for information only. It cannot replace a check-up, and your doctor can interpret the numbers for your own situation.
Is what I enter in this calculator saved or sent anywhere?
No. The calculation runs in your browser, so what you enter is not sent to our servers. We only count, anonymously, whether a tool ran successfully.
Is this calculator free to use?
Yes. It is free, needs no sign-up and has no usage limit.
Last reviewed: October 3, 2026