📉Calorie Deficit Calculator

About this tool

Enter your current and goal weight (kg or lb), your maintenance calories (TDEE) and how much you plan to eat each day. The tool shows the daily deficit, the expected weekly loss, the number of weeks to your goal and an estimated goal date. A table lists the daily intake for slower and faster rates. It flags intakes below common minimums and losses above about 1% of body weight a week. Nothing is stored.

How a calorie deficit works

You lose weight when you eat fewer calories than you burn. Your maintenance calories (total daily energy expenditure, or TDEE) are what you'd eat to stay the same weight; anything below that is the deficit. A common rule of thumb is that about 7,700 kcal equals 1 kg of body fat, or 3,500 kcal per pound. A 500 kcal daily deficit is therefore about 3,500 kcal a week, roughly 0.45 kg (1 lb). In the example, eating 1,900 kcal against 2,400 maintenance takes about 22 weeks to lose 10 kg. Most guidance suggests losing 0.5–1 kg (1–2 lb) a week. Slower is easier to sustain and protects muscle, especially if you eat enough protein and do strength training. Very low intakes, below about 1,200 kcal a day for women or 1,500 for men, are generally only advised under medical supervision. Honest limits: the 7,700 kcal rule is a simplification. Early losses are partly water, and as you get lighter your maintenance falls, so progress slows unless you recalculate every few kilos. Not medical advice: speak to a GP or dietitian if you're pregnant, under 18 or have a health condition. Find your maintenance figure with the calorie calculator, split it with the macro calculator, and read How daily calorie needs are calculated — BMR, activity multipliers and what a deficit means.

Frequently asked questions