Calorie Deficit Calculator
Turn a calorie deficit into expected weekly and monthly weight loss.
Daily deficit
500 kcal
Expected weekly loss
0.45 kg (1 lb)
Monthly
2 kg
Deficit size
21%
Sustainable deficits run 10–25% of maintenance; larger cuts sacrifice muscle and adherence.
The energy ledger
A kilogram of body fat stores roughly 7,700 kcal, so a 500 kcal daily deficit projects ~0.45 kg (1 lb) weekly. Reality bends the line: water shifts mask early progress, and metabolism adapts modestly as weight falls — recalculate TDEE every 5 kg.
Keep the deficit honest
Logging errors run 20–40% for most people, and 'exercise calories' from trackers are generous. The scale averaged over a week is the ground truth: if it isn't moving after three weeks, the deficit isn't what the plan says it is.
Frequently asked questions
- How does the Calorie Deficit Calculator work?
- Turn a calorie deficit into expected weekly and monthly weight loss.
- Is the Calorie Deficit Calculator free to use?
- Yes. The Calorie Deficit Calculator is completely free, runs entirely in your browser, and requires no account or sign-up. Your inputs never leave your device.
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