Calorie Deficit Calculator
Calculate how many calories to eat per day to lose weight, burn fat and reach your target weight with a realistic date
What is a calorie deficit?
A calorie deficit occurs when you consume fewer calories than your body burns (TDEE). It is the only scientifically proven mechanism for sustained fat loss and weight loss. A deficit of approximately 7,700 kcal is equivalent to the loss of 1 kg of body fat. Very aggressive deficits (> 1,000 kcal/day) can compromise muscle mass, which is why maintaining a high protein intake (≥ 2.0 g/kg) is especially important during the weight-loss phase. Dive deeper with our article on how much calorie deficit is safe.
How to plan your weight-loss deficit
Enter your sex, age, height and activity level so we can calculate your TDEE. Then enter your current weight, your target weight and your preferred weight-loss pace. The calculator determines the required daily deficit, shows you an estimated goal date and warns you if the deficit is too aggressive (below 1,200 kcal/day). A sustainable deficit for losing weight is 300–500 kcal/day. To preserve muscle while losing fat, make sure to keep protein intake high.
Weight-loss rates by deficit
| Daily deficit | Weekly loss | Rate | Recommendation |
|---|---|---|---|
| 250 kcal | ~0.25 kg | Mild | Ideal for body recomposition |
| 500 kcal | ~0.5 kg | Moderate | Recommended for most people |
| 750 kcal | ~0.75 kg | Aggressive | Only with professional supervision |
| 1,000 kcal | ~1 kg | Very aggressive | Risk of muscle loss and rebound |
Calorie deficits and their health effects
Very gradual weight loss. Ideal for body recomposition or people with little excess weight. Minimal risk of muscle loss. Sustainable indefinitely.
The optimal range for most people. Loss of 0.3–0.5 kg/week while preserving muscle mass. Compatible with strength training and moderate intensity exercise.
Faster weight loss but higher risk of fatigue and muscle loss. Requires high protein intake (≥ 2.2 g/kg) and weekly monitoring. Not recommended for more than 8–12 weeks.
High risk of muscle loss, hair loss, nutritional deficiencies and metabolic adaptation. Can cause rebound weight gain when returning to normal eating.
Minimum safety threshold for women (1,500 kcal for men). Below this level the risk of malnutrition increases significantly. Mandatory medical supervision required.
FAQ
1How much is a safe calorie deficit to lose weight?
A deficit of 300–500 kcal/day is safe for most people, allowing a loss of 0.3–0.5 kg/week while preserving muscle mass. Deficits above 1,000 kcal/day can cause muscle loss, fatigue and rebound weight gain.
2What is the minimum number of calories I should eat per day?
The generally recommended minimum is 1,200 kcal/day for women and 1,500 kcal/day for men. Below these values the risk of nutritional deficiencies and muscle loss increases significantly. Always under professional supervision.
3Does a calorie deficit cause muscle loss?
A moderate deficit (300–500 kcal/day) with high protein intake (≥ 2.0 g/kg of body weight) preserves muscle mass very well. The risk of losing muscle increases significantly with aggressive deficits and insufficient protein. Strength training also protects muscle during weight loss.
4How much weight can I lose in a month with a calorie deficit?
With a moderate deficit of 500 kcal/day you can expect to lose approximately 2 kg per month (0.5 kg/week). With a deficit of 250 kcal/day the loss would be 1 kg/month. Losing more than 4 kg/month sustainably involves very aggressive deficits with a risk of muscle loss.
5Can I lose fat without feeling hungry?
Yes. Strategies like prioritizing protein and fiber, distributing meals throughout the day, and choosing high-satiety, low-calorie foods (fruits, vegetables, legumes) allow you to maintain a deficit with less hunger.
6What happens if I have too large a calorie deficit?
An excessive deficit slows metabolism (metabolic adaptation), promotes muscle loss, causes fatigue, nutritional deficiencies and increases the risk of regaining lost weight (rebound) when returning to normal eating.
7Does a calorie deficit work the same for everyone?
The principle is universal, but the exact amount varies by individual metabolism, activity level, body composition and hormonal factors. It's important to adjust based on real results after 2–3 weeks.
8Is the calorie deficit different for women and men?
The mechanism is the same, but women typically have a lower TDEE and different minimum thresholds (1,200 kcal vs 1,500 kcal). Hormonal fluctuations can also affect water retention week to week, without implying real changes in body fat.
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