Calorie Deficit to Lose 1 kg a Week

The figure comes straight from the energy a kilogram of fat holds. Body fat stores about 7,700 calories per kilogram, so to shed one in a week you need a weekly shortfall of roughly 7,700 calories, and dividing that across seven days lands on about 1,100 a day. That is why ‘1 kg a week’ and ‘an 1,100 deficit’ are two ways of saying the same thing. As with every deficit, the 1,100 is the gap below your maintenance burn rather than the food on your plate — the number you actually eat is your Total Daily Energy Expenditure minus the 1,100. It is worth noticing how large that gap is next to the more familiar rates: it is more than double the popular 500-a-day deficit, and a clear step beyond even the aggressive 750. The size is the whole reason this pace is harder to sustain than it first looks, and why the result the calculator returns deserves a careful read rather than a glance. If you would rather frame the same maths as a target weight by a date, the Goal Weight Calculator projects when you would arrive.

Whether a full 1,100 deficit is even reachable comes down to your maintenance burn, and for a lot of people it is not. Subtract 1,100 from a maintenance figure of 2,600 and you are eating 1,500; subtract it from 2,000 and you are at 900 — well under any sensible minimum. The calculator will not set a target below 1,200 calories for women or 1,500 for men, so when an 1,100 deficit would carry intake past that line, the tool caps the intake at the floor, reports the smaller deficit the floor produces, and shows a banner explaining the cap. That banner is a factual flag, not a verdict on you: it is simply pointing out that, for your numbers, a full 1,100 deficit and a safe minimum intake cannot both hold. Larger or very active bodies with high maintenance figures can sometimes clear the floor and support the pace; smaller or more sedentary ones generally cannot, and will see the cap appear. The honest way to find out which group you are in is to enter your details above, and to pin down the maintenance figure the 1,100 is measured against the TDEE Calculator estimates it from your stats.

0.5 kg a Week Is the Gentler Alternative

If the calculator caps your 1 kg pace, the natural next step is to halve the target. Half a kilogram a week needs a deficit of only about 550 calories a day, which is close to the well-worn 500 most plans build around and far more likely to keep your intake comfortably above the floor. The scale moves at half the headline speed, but it keeps moving without the hunger, energy dips and adherence strain that a 1,100 gap tends to bring — and a rate you can hold for months beats a faster one you abandon in a fortnight. Many people get further treating 1 kg a week as an occasional short push, if at all, and settling on the gentler pace as their default. The Calorie Deficit Calculator lets you compare 0.5 kg and 1 kg side by side with your own numbers, so the trade-off between speed and what you actually eat is concrete. These figures are general estimates for healthy adults, not medical advice.