Calorie Deficit for Weight Loss Calculator
Enter your maintenance calories and your weekly weight loss goal to see the daily calorie deficit and target intake needed to get there.
Calorie Deficit for Weight Loss Calculator
Calculates the daily calorie deficit and target daily calories needed to reach a chosen weekly weight loss goal.
This calculator converts a weekly weight-loss goal into a daily calorie target by using the common approximation that roughly 7,700 kilocalories corresponds to one kilogram of body fat, spreading that total deficit evenly across seven days and subtracting it from your maintenance calorie level. It's a standard first-pass planning tool for anyone setting a calorie target, though actual results vary by individual metabolism, activity changes, and body composition — pairing it with professional guidance is recommended for sustained or significant weight loss.
Example
- With the default values shown above, this calculator returns: Daily Calorie Deficit Needed ≈ 550 kcal/day; Target Daily Calories ≈ 1650 kcal/day.
Frequently Asked Questions
Where does the 7,700 kcal figure come from?
It's a commonly cited approximation for the number of kilocalories roughly equivalent to one kilogram of body fat, used to translate a weight-loss goal into a calorie deficit.
Is a bigger deficit always better?
Not necessarily — very large deficits are harder to sustain and can affect energy levels, muscle mass and metabolism; many guidelines suggest a moderate, sustainable deficit (often around 0.5 kg/week) rather than the fastest possible rate.
What if the target calories look too low?
If the target daily calories come out unrealistically low, consider a smaller weekly weight-loss goal — a very aggressive deficit is often not sustainable or advisable without professional guidance.
Sources
- Standard formula, publicly documented method