Calorie Deficit Calculator
Calculate the daily calorie deficit needed to reach your goal weight by your target date, based on the 7,700 kcal per kg of fat principle.
Results
What is it?
The Calorie Deficit Calculator determines how many fewer calories per day you need to eat (relative to your TDEE) in order to lose a specific amount of weight within a set timeframe. It is based on the principle that 1 kg of body fat stores approximately 7,700 kcal of energy (equivalent to 3,500 kcal per pound). Your Total Daily Energy Expenditure (TDEE) is the number of calories your body burns in a day including all activity.
How to use
1. Enter your current weight and goal weight (both in the same unit). 2. Enter your target timeframe in weeks. 3. Enter your TDEE (use the TDEE/BMR calculator if you do not know it). 4. The calculator shows your required daily deficit and your calorie intake target. 5. If the daily deficit exceeds 1,000 kcal or the daily intake drops below ~1,200 kcal (women) / 1,500 kcal (men), extend the timeframe.
Example scenario
Current: 85 kg, Goal: 75 kg, 12 weeks, TDEE: 2,200 kcal. Weight to lose: 10 kg. Total deficit: 77,000 kcal. Daily deficit: 77,000 / 84 days = 917 kcal/day. Daily intake target: 2,200 - 917 = 1,283 kcal. Weekly loss: 10 / 12 = 0.83 kg/week.
Pro tip
A deficit above 1,000 kcal/day or more than 1 kg/week increases the risk of muscle loss — the body breaks down lean tissue for energy when the deficit is too aggressive. Preserve muscle by keeping protein intake high (1.6-2.2 g/kg body weight) and including resistance training. Calorie needs also decrease as you lose weight, so recalculate your TDEE every 4-6 weeks.