Calorie deficit calculator
How many calories should you eat to lose weight at the rate you want? Pick a weekly goal and get a daily target.
How it works
About 7,700 kcal of deficit corresponds to roughly 1 kg of body fat (about 3,500 kcal per pound). So losing 0.5 kg a week needs a deficit of about 550 kcal a day:
Daily target = TDEE − (weekly loss in kg × 7,700 ÷ 7)
| Weekly loss | Daily deficit |
|---|---|
| 0.25 kg (½ lb) | ≈ 275 kcal |
| 0.5 kg (1 lb) | ≈ 550 kcal |
| 0.75 kg (1½ lb) | ≈ 825 kcal |
| 1 kg (2 lb) | ≈ 1,100 kcal |
A slower rate is easier to sustain and helps keep muscle. Targets are never set below 1,200 kcal (1,500 kcal for men). Weight loss usually slows over time as your body gets smaller, so recalculate every few kilograms.
The formula
We use the Mifflin-St Jeor equation, which studies have found to be the most accurate of the common equations for estimating resting energy expenditure in healthy adults:
Men: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age + 5
Women: BMR = 10 × weight (kg) + 6.25 × height (cm) − 5 × age − 161
If you prefer not to give a sex, we use the midpoint of the two (−78). Your BMR is then multiplied by an activity factor to estimate total daily energy expenditure (TDEE):
| Activity level | Description | Multiplier |
|---|---|---|
| Sedentary | Little or no exercise, desk job | 1.2 |
| Lightly active | Exercise 1–3 days a week | 1.375 |
| Moderately active | Exercise 3–5 days a week | 1.55 |
| Very active | Hard exercise 6–7 days a week | 1.725 |
Read more: Calorie deficit, explained.
FAQ
Frequently asked questions
What is a good calorie deficit?
For most people, 300–500 kcal a day, which leads to about 0.25–0.5 kg (½–1 lb) of loss a week. Larger deficits are harder to sustain.
Why am I not losing weight in a calorie deficit?
Usually the deficit is smaller than it seems: portions are underestimated, or water retention hides fat loss for a week or two. Track consistently for 2–3 weeks and look at the trend.
Is a 1,000 calorie deficit safe?
It may be too aggressive for many people and can cost muscle. Talk to a doctor before eating very little.