About the Calorie Deficit Calculator
What is the Calorie Deficit Calculator?
You lose fat when you eat fewer calories than you burn. This calorie deficit calculator works out your maintenance calories and subtracts the deficit you choose.
It shows the expected weekly loss and checks that your target stays above the minimum intake (1,200 kcal for women, 1,500 kcal for men) and the safe pace of up to 1% of body weight a week.
How to use the Calorie Deficit Calculator
- Sex (sample: Male)
- Weight (kg) (sample: 78)
- Height (cm) (sample: 172)
- Age (years) (sample: 32)
- Activity Level (sample: Lightly active – exercise 1–3 days a week (×1.375))
- Daily Calorie Deficit (kcal) (sample: 500)
- Press Calculate Calorie Deficit (results also refresh as you type). The result card shows the Daily Calorie Target, along with Maintenance calories, Expected weight loss per week, Deficit as % of maintenance and Time to lose 5 kg.
Formula used
Calorie target = TDEE − Daily deficit
- Weekly loss = deficit × 7 ÷ 7,700 kg
A deficit of 300–500 kcal (about 15–25% of maintenance) is sustainable for most people.
Worked example
These are the sample values already filled in the calculator above, and the result it returns for them:
| Input | Sample value |
|---|---|
| Sex | Male |
| Weight (kg) | 78 |
| Height (cm) | 172 |
| Age (years) | 32 |
| Activity Level | Lightly active – exercise 1–3 days a week (×1.375) |
| Daily Calorie Deficit (kcal) | 500 |
| Result | Value |
|---|---|
| Daily Calorie Target | 1,838 kcal |
| Maintenance calories | 2,338 kcal |
| Expected weight loss per week | 0.45 kg |
| Deficit as % of maintenance | 21.4% |
| Time to lose 5 kg | 11 weeks |
| Safety check | Safe, sustainable pace |
Tips for using the Calorie Deficit Calculator
- Keep protein high (1.6–2.2 g per kg) to protect muscle while dieting.
- Very large deficits cause fatigue, muscle loss and rebound weight gain.