What this calculator does
This tool turns your maintenance calories (TDEE) and a chosen calorie deficit percentage into a concrete daily calorie target for fat loss. It also estimates how big your weekly deficit will be and how much body fat that could translate to per week, in both kilograms and pounds.
How to use it
Enter your TDEE (total daily energy expenditure) — the number of calories you burn on an average day. Then choose a deficit percentage. A 10–20% deficit is generally considered moderate and sustainable, while larger deficits lose weight faster but are harder to maintain. The calculator subtracts the deficit and shows your daily cutting calories.
The formula explained
$$\text{Cutting Calories} = \text{TDEE} \times \left(1 - \frac{\text{Deficit \%}}{100}\right)$$ The daily deficit \(\left(\text{TDEE} \times \frac{\text{Deficit \%}}{100}\right)\) multiplied by 7 gives a weekly deficit. Dividing the weekly deficit by 7,700 kcal estimates fat loss in kilograms, and dividing by 3,500 kcal estimates fat loss in pounds, since roughly that many calories are stored per unit of body fat.
Worked example
With a TDEE of 2,500 kcal and a 20% deficit: the daily deficit is $$2{,}500 \times 0.20 = 500 \text{ kcal},$$ so the daily target is 2,000 kcal. Over a week the deficit is 3,500 kcal, which is about 0.45 kg or 1.0 lb of fat per week.
FAQ
How big a deficit should I use? Most people do well with 10–25%. Very aggressive cuts risk muscle loss and fatigue.
Why don't I lose exactly the predicted weight? Water shifts, glycogen, and metabolic adaptation make real-world results vary. Use it as an estimate, not a guarantee.
Where do I get my TDEE? Use a TDEE or maintenance-calorie calculator based on your activity level, then plug the number in here.
