The Calculation, Step by Step
Choosing Your Deficit Size
| Goal | Daily Deficit | Weekly Loss | Best For |
|---|---|---|---|
| Slow, steady | ~250 kcal | ~0.25 kg | Small amounts to lose, minimal hunger, long-term habits |
| Moderate | ~500 kcal | ~0.5 kg | Most people, balances speed and sustainability |
| Aggressive | 750–1000 kcal | 0.75–1 kg | Short, defined phases only — higher muscle loss risk |
Don’t go below your BMR. Whatever deficit you choose, your final calorie target should still sit comfortably above your BMR — eating at or under it for extended periods risks fatigue, muscle loss and rebound overeating rather than faster results. See BMR vs TDEE for why this distinction matters.
Worked Example
Someone with a TDEE of 2,556 cal/day choosing a moderate 500-calorie deficit would target roughly 2,056 cal/day. If their BMR is 1,649, that target still sits comfortably above it — a sustainable, defensible deficit rather than a crash diet.
Protecting Muscle While You Diet
1 Keep lifting weights
Resistance training signals your body to preserve muscle even in a deficit; cardio-only weight loss tends to lose more muscle for the same amount of fat lost.
2 Hit your protein target daily
Protein is the most muscle-sparing macronutrient during a cut. Check the macro breakdown on our calculator for your specific gram target.
Common Mistakes That Stall Progress
- Underestimating portions — untracked intake is commonly underestimated by 20–30%, even by confident estimators.
- "Eating back" exercise calories — fitness trackers and gym machines often overstate calories burned.
- Judging by daily scale weight — water retention shifts weight by 1–2 kg daily; use weekly averages instead.
- Cutting too hard, too fast — leads to fatigue, poor training performance and binge-restrict cycles.
Frequently Asked Questions
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