A weight loss calorie calculator determines how many calories you should eat each day to lose fat. It starts with your maintenance calories and subtracts a deficit for weight loss.
How a weight loss calorie calculator works
The calculator follows these steps:
- Calculate your BMR (Mifflin-St Jeor equation)
- Apply activity factor to get TDEE/maintenance
- Select weight loss goal (mild, moderate, aggressive)
- Subtract appropriate deficit (250–1,000 calories)
- Apply safety minimums (1,500 men, 1,200 women)
Try our calorie calculator for automatic weight loss targets.
Weight loss calorie targets by deficit
| Deficit | Weekly Loss | Target for 2,500 maintenance |
|---|---|---|
| Mild (250 kcal) | ~0.5 lb (0.25 kg) | 2,250 calories/day |
| Moderate (500 kcal) | ~1 lb (0.5 kg) | 2,000 calories/day |
| Large (750 kcal) | ~1.5 lb (0.7 kg) | 1,750 calories/day |
| Extreme (1,000 kcal) | ~2 lb (1 kg) | 1,500 calories/day (minimum) |
Safe weight loss calorie ranges
For sustainable fat loss:
- Women: Minimum 1,200 calories/day (medical supervision below)
- Men: Minimum 1,500 calories/day
- Moderate deficit: 300–500 calories below maintenance
- Goal rate: 0.5–2 lb per week is considered safe
Adjusting a weight loss calorie calculator
If weight loss stalls after 2–3 weeks:
- Verify tracking accuracy (weigh food, log everything)
- Recalculate maintenance if you've lost 4–5 kg
- Adjust intake by 100–200 calories if needed
- Check activity level hasn't changed
Why weight loss calorie calculators sometimes fail
- Overestimating activity level inflates maintenance
- Under-reporting calorie intake
- Metabolic adaptation during weight loss
- Changes in non-exercise activity (NEAT)
- Medical conditions affecting metabolism
Combining calorie targets with macros for weight loss
Optimize your weight loss with protein:
- Protein: 1.6–2.2 g per kg of body weight
- Fat: 20–30% of total calories
- Carbs: Remainder of calories
Use our protein calculator and macro calculator alongside your calorie target.