Calorie Deficit Calculator
A calorie deficit occurs when you consume fewer calories than your body expends, forcing it to draw on stored fat for energy. By knowing your Total Daily Energy Expenditure (TDEE) — the number of calories you burn each day — you can set a precise daily intake target to lose a specific amount of weight within a chosen timeframe.
The standard energy equivalents are 7,700 kcal per kilogram of body fat (or 3,500 kcal per pound). Dividing your total required deficit by the number of days in your plan gives your daily deficit. Health experts generally recommend keeping the deficit below 1,000 kcal/day and your daily intake above 1,200 kcal to avoid muscle loss, nutrient deficiencies, and metabolic slowdown.
How it works
Total deficit (kcal) = target weight loss × 7,700 (kg) or × 3,500 (lb). Daily deficit = Total deficit ÷ (weeks × 7). Daily intake = TDEE − daily deficit.
Use cases
- Planning a structured weight-loss program with a specific goal date
- Checking whether a proposed diet is medically safe before starting
- Adjusting calorie targets after a plateau or change in activity level
- Comparing outcomes for different timeframes (e.g., 8 vs. 16 weeks)
- Estimating how many calories to cut per day to lose 1–2 kg per month