What is a calorie deficit?
Eating fewer calories than your body uses over the same period. This tool takes the maintenance figure you enter, subtracts the daily deficit you choose, and shows the intake that leaves you with.
What is my target if my maintenance is 2,200 and I want a 500 calorie deficit?
1,700 calories a day, and the estimated change is 0.45 kg a week. That comes from 500 times 7, which is 3,500 calories a week, divided by the 7,700 calories per kilogram convention.
How much does a 300 calorie deficit give me per week?
About 0.27 kg. A 750 calorie deficit gives about 0.68 kg and a 1,000 calorie deficit gives about 0.91 kg. These are projections from a fixed conversion, not measurements, and individual results vary.
How is the weekly figure calculated?
Daily deficit multiplied by 7, divided by 7,700, shown to two decimal places in kilograms. Your maintenance calories and body weight do not enter into it, which is why the same deficit shows the same weekly figure for everyone.
Is the 7,700 calories per kilogram figure real?
It is a reasonable estimate of the energy stored in a kilogram of body fat, but using it to predict change over time is where it breaks. Weight lost is a mixture of fat, lean tissue, and water, and expenditure changes as you go.
What happens if my deficit is bigger than my maintenance?
The tool floors the target at zero and adds a line saying the deficit is larger than maintenance, so the target is not a real intake. That is a broken input rather than an aggressive plan, and it is worth rechecking both numbers.
Why did I lose more in week one than the calculator predicted?
Glycogen. Each gram of stored carbohydrate holds around 3 grams of water, so cutting calories drops a couple of kilograms of water in the first week that has nothing to do with fat. It comes back the moment you eat normally again.
Why has my change slowed even though I have not altered anything?
Because a smaller body burns less. The 7,700 calorie rule assumes maintenance stays fixed, and it does not. Recalculate your maintenance every few kilograms and expect to adjust over time to hold the same deficit.
How big a deficit is reasonable?
Around 500 calories a day is the figure most commonly cited for someone at a normal weight, giving roughly half a kilogram a week. Larger deficits are harder to sustain and increase muscle loss, and daily intakes below about 1,200 calories should be medically supervised.
Where do I get my maintenance calories?
From the TDEE calculator or the calorie calculator, both of which estimate maintenance from your weight, height, age, sex, and activity level. Pick the conservative activity option, since an inflated maintenance figure quietly shrinks the deficit you think you are running.
Does it work in pounds?
The weekly figure is reported in kilograms only. The calorie fields are plain numbers, so they work with whatever calorie figures you already track, but the weight output does not convert. Multiply by 2.205 for pounds.
Should I also plan my protein and carbs?
Many people do. The macro calculator takes a daily calorie target like the one this tool produces and splits it into grams of protein, carbohydrate, and fat. What split suits you is a question for a dietitian rather than for arithmetic.
Is the calorie deficit calculator free?
Yes. It is completely free to use, with no signup, no account, and no paywall.
Does the calculator send my numbers anywhere?
No. It is a subtraction and a division running in your browser as you type. Nothing is uploaded.
Are the results medical advice?
No. The output is a general estimate built from a standard conversion and population averages, and real results vary between individuals. For decisions about your health, diet, or training, check with a doctor or registered dietitian.