Calorie deficit
How Many Calories Does It Take to Lose 1 kg?
A common planning estimate is that losing 1 kg of body fat requires a cumulative calorie deficit of roughly 7700 kcal. In practice, real weight loss is rarely perfectly linear, but this is a useful rule of thumb for planning.
Quick answer
Rough total deficit
7700
kcal
500 kcal/day
~15
days per 1 kg
1000 kcal/day
~8
days per 1 kg
Calorie deficit calculator
Estimated TDEE
2875
Calories/day
Estimated daily deficit
1100
Calories/day
Estimated target intake
1775
Calories/day
This is a planning estimate based on common energy-balance assumptions. Real-world weight loss varies based on adherence, water shifts, body composition, and metabolic adaptation.
What 7700 kcal actually means
The 7700 kcal rule is a simplified estimate based on the energy stored in 1 kg of body fat. It is useful for planning, but your body is not a perfectly static machine.
Water retention, adherence, food intake accuracy, training, sleep, and metabolic adaptation all affect what happens in real life.
Example daily deficits
- 250 kcal/day deficit: about 31 days per 1 kg
- 500 kcal/day deficit: about 15 days per 1 kg
- 750 kcal/day deficit: about 10 days per 1 kg
- 1000 kcal/day deficit: about 8 days per 1 kg
Common mistakes
- Treating the 7700 kcal rule as exact rather than approximate
- Ignoring water-weight fluctuations
- Using a deficit that is too aggressive to sustain
- Expecting the same rate of loss forever