Free Tool
Calorie Deficit Calculator
Enter your stats, pick a target weight and a weekly loss rate. Get your daily deficit, calorie target, protein range, and goal date.
How the Calorie Deficit Works
A calorie deficit is the only mechanism that produces fat loss. The size of the deficit determines how fast you lose, but bigger is not always better. Go too aggressive and your body breaks down muscle along with fat.
The Math
One kilogram of body fat is about 7,700 calories (one pound is about 3,500 calories). To lose 0.5 kg per week, you need a deficit of roughly 550 cal/day. For 1 kg/week, ~1,100 cal/day. This calculator subtracts your chosen daily deficit from your TDEE to give your target intake.
Track the same target for at least 2 weeks before adjusting. Daily water-weight swings can hide real progress. Use a 7-day weight average and trust the trend, not single-day readings.
For the deeper write-up on adjusting as you lose, why aggressive deficits backfire, and protein in a cut, read the full article: Calorie Deficit Calculator: How to Calculate Your Deficit for Fat Loss.