Calorie Deficit Calculator
Plan your weight loss: enter your goal weight and pace to get your daily calorie target, deficit and the date you'll reach your goal. Free.
- Daily deficit
- 550 kcal
- Calories to maintain your weight
- 2,633 kcal/day
- Weight to lose
- 7 kg
- Time to reach your goal
- 14 weeks
- Goal date
- –
An estimate from a published formula, for general information. It isn't medical advice; talk to a doctor or dietitian about your own needs.
How a calorie deficit works
You lose weight when you eat fewer calories than you burn. The calculator estimates your maintenance calories, then works out the daily deficit for the pace you choose, using the standard figure of about 7,700 kcal per kilogram of fat (3,500 per pound). It tells you how many calories to eat each day, how many weeks it will take and the date you'll reach your goal at that pace. Losing 0.5–1% of your body weight a week is a safe, sustainable rate for most people; the target never drops below the usual minimum of 1,200 kcal (women) or 1,500 kcal (men).
How to use it
- 1
Enter your details
Your sex, age, height, current weight and activity level.
- 2
Set your goal
Enter your goal weight and how fast you want to lose it.
- 3
Follow the plan
Eat about the daily target and check your weight weekly. Weight loss slows as you get lighter, so recalculate every few kilos.
Frequently asked questions
How big should my calorie deficit be?
300–500 kcal a day suits most people and keeps hunger and muscle loss down. 750–1,000 kcal a day is aggressive and best for people with a lot of weight to lose.
Why does weight loss slow down?
As you lose weight you burn fewer calories, so the same intake becomes a smaller deficit. Recalculate with your new weight every 4–5 kg.
Why did I lose more in the first week?
Early losses include water and stored carbohydrate (glycogen), not just fat. After the first week or two, the rate settles closer to the plan.
Is anything sent to a server?
No. Everything is calculated in your browser, and nothing you type is stored or sent anywhere.