Calorie Deficit Calculator
Find out how long it will take to reach your weight loss goal at your current calorie deficit.
Assumptions used in this calculation
- Constant deficit: Assumes your maintenance calories and adherence stay constant, real-world weight loss often isn't perfectly linear.
About this calculator
Setting a lower calorie target is easy, but knowing how long it will actually take to lose a specific amount of weight at that target requires converting a daily deficit into a timeline, using the commonly cited figure that roughly 7,700 kcal corresponds to one kilogram of body fat. This calculator takes your maintenance calories (TDEE), your target daily calories, and how much weight you want to lose, subtracts target from maintenance to find your daily deficit, then divides your total weight-loss goal (converted to kcal) by that daily deficit to estimate the number of weeks and days until you reach your goal. Rather than guessing at a rough timeframe or under/overestimating how aggressive a given deficit really is, you get a concrete week-by-week estimate tied directly to the numbers you entered. Real-world weight loss isn't perfectly linear, water retention, adherence, and metabolic adaptation all cause deviation, so treat the result as a planning estimate rather than a guaranteed schedule.
Worked example
2,200 kcal maintenance, 1,700 kcal target, 5kg to lose
Result: ≈ 11 weeks to goal
Was this helpful?