Calorie deficit calculator
Pick a goal weight and how fast you want to get there, and this works out the daily calories and how many weeks it will take. It also recalculates the target as you get lighter, which is the step most plans skip.
Rates are set as a percentage of your bodyweight per week, not a fixed number, because a kilogram a week is a very different demand at 60 kg than at 120 kg.
- Estimated maintenance
- 2,740 kcal
- Daily deficit
- 528 kcal
- Time to goal
- 17 weeks
An estimate from a published formula, not a measurement. Use it as a consistent yardstick for tracking change.
How the target moves as you get lighter
Maintenance falls with bodyweight, so a fixed calorie number becomes a smaller and smaller deficit. This is why loss stalls around week eight on plans that never revisit the figure.
| Week | Projected weight | Target that week |
|---|---|---|
| 0 | 80 kg | 2,212 |
| 2 | 79 kg | 2,197 |
| 4 | 78.1 kg | 2,182 |
| 6 | 77.1 kg | 2,167 |
| 8 | 76.2 kg | 2,152 |
| 10 | 75.2 kg | 2,137 |
| 12 | 74.2 kg | 2,122 |
Why the rate is a percentage
Half a kilogram a week is a modest deficit for someone at 110 kg and an aggressive one for someone at 55 kg. Expressing the rate as a percentage of current bodyweight keeps the demand proportional, which is why coaches write it that way.
Roughly 0.5 to 0.7% a week is the range most people can hold while keeping their training quality. Faster is possible and costs more lean mass, more hunger, and more adherence.
The 7,700 kcal figure and what it hides
A kilogram of body fat stores roughly 7,700 kcal, and that is the conversion used here. It is a fair approximation for the fat you lose, but real weight loss is never purely fat: early weeks include water and glycogen, and some lean tissue goes with the fat unless protein and training defend it.
So the arithmetic is honest about energy and optimistic about composition. Keep protein high and keep lifting, and the split moves in your favour.
Why the calculator holds a floor
If the goal and the rate you picked would put you below roughly your basal rate, the target is clamped there and the card changes colour. Eating under your basal expenditure for an extended period is where lean mass loss, hormonal disruption and eventual rebound live.
Seeing the floor means one of two things needs to change: the rate is too aggressive, or the activity side of the equation needs to do more of the work.
What to do when the scale stalls
A week of no change is noise. Three weeks of no change on a weekly average is a stall worth acting on. The usual causes, in order of likelihood: intake has crept up without being logged, spontaneous movement has fallen, and maintenance has dropped because you are lighter.
The fix is rarely a bigger deficit. More often it is a diet break at maintenance for a week or two, then resuming with a recalculated number.
Questions people ask
How big should a calorie deficit be?
For most people, 15 to 25% below maintenance. That lands around 0.5 to 0.7% of bodyweight per week, which is fast enough to see progress and slow enough to keep training quality and lean mass.
Why did I lose 2 kg in the first week?
Mostly water and glycogen. Every gram of stored glycogen holds several grams of water, and lowering carbohydrate intake drops both quickly. It is real weight but it is not fat, and it does not repeat in week two.
Can I build muscle in a deficit?
Yes, in specific cases: new lifters, people returning after a break, and those with higher body fat. It is slow and it needs high protein and hard training. If that is your situation, the body recomposition calculator is built for it.
Should I eat back the calories I burn training?
No, if your activity multiplier already accounts for those sessions. Adding them again is double counting and it is the most common reason a carefully planned deficit produces no loss.
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