Calorie Deficit Calculator
Build a calorie deficit that fits your goal
A calorie deficit means eating less than you burn. The size of that deficit determines how fast you lose weight — and how sustainable it is. We size your deficit as a percentage of your bodyweight, not a flat number.
Example deficit
440kcal/day
Example result — your number is calculated from your own data in the full calculator.
Get My NumberSized to your bodyweight
Choose a rate of loss expressed as a percentage of your current bodyweight per week, from gentle to aggressive.
Built on your maintenance level
Your deficit is calculated from your estimated maintenance calories, not an arbitrary starting number.
Testable, not fixed
Every deficit is a starting hypothesis. Check-ins confirm whether it matches your real-world results.
Common questions
How big should my calorie deficit be?
It depends on your goal and how sustainable you need it to be. Gentle deficits (around 0.25% of bodyweight/week) are easier to maintain; larger deficits produce faster results but are harder to sustain.
Will a bigger deficit work faster?
A larger deficit can produce faster short-term loss, but it increases the risk of muscle loss, low energy and poor adherence. Our rate options are classified from Gentle to Aggressive to help you choose deliberately.
What if I stop losing weight?
This is exactly what the 14-day check-in is for — comparing your predicted progress with what actually happened and adjusting if needed.