How to Calculate a Calorie Deficit
A calorie deficit means your average intake sits below your average burn (TDEE). The practical calculation is: estimate maintenance → subtract a moderate percentage (often ~15–20%) → eat that target → confirm with weekly weight trends.
You do not need a mystery “500 calorie rule” if you do not know maintenance first.
Direct formula (educational)
- TDEE = estimated maintenance
- Deficit calories/day ≈ TDEE × 0.15 to 0.20 (moderate)
- Daily target = TDEE − deficit
- Keep protein high; stay above educational planning floors used on Protealpes (~1,200 kcal women / ~1,500 kcal men in-tool)
Tools: calorie deficit calculator · TDEE calculator · calorie calculator
Step-by-step
1. Find maintenance
Use the TDEE calculator or the 2-week method in find maintenance calories.
2. Choose deficit size
| Deficit | Approx. cut from TDEE | Typical use |
|---|---|---|
| Mild | ~10–15% | Slow fat loss, training-heavy |
| Moderate | ~15–20% | Default for most adults |
| Aggressive | >25% | Higher risk to muscle/adherence |
Related context: calorie deficit vs surplus.
3. Set protein
Many active adults in a cut land near ~1.6–2.2 g/kg (ISSN-aligned educational ranges). Use the protein calculator and protein for fat loss.
4. Fill carbs and fat
Remaining calories → macro calculator.
5. Verify for 2 weeks
Average 7 morning weights. If flat with honest logging, trim 100–200 kcal or add steps — don’t slash 500 kcal in panic. See weight loss plateau.
Worked example
- TDEE: 2,500 kcal
- 20% deficit: 500 kcal
- Target: 2,000 kcal/day
- Body weight 80 kg → protein 160 g (~2.0 g/kg) ≈ 640 kcal
- Remaining 1,360 kcal for carbs + fat
500 kcal deficit vs percentage deficit
| Method | Pros | Cons |
|---|---|---|
| Fixed −500 kcal | Simple | Harsh on small TDEEs; mild on large ones |
| % of TDEE | Scales to body/activity | Needs a decent TDEE estimate |
Percentage usually travels better across body sizes.
Logging that keeps the math honest
- Count oils, creamers, alcohol
- Use cooked weights when possible
- For mixed plates: AI meal analyzer
- Prefer USDA-matched rows; treat unmatched as estimated
Key takeaway: Calorie deficit = eat below TDEE on average. Calculate target from maintenance × a moderate percent, protect protein, and let weekly averages — not daily scale mood — judge the plan.
FAQ
How fast should the scale move?
Many educational plans aim near 0.25–0.75% of body weight per week. Individuals vary.
Can I create a deficit with exercise only?
Yes, but diet control is usually more reliable. Activity helps health and may raise TDEE.
What if hunger wrecks adherence?
Shrink the deficit, raise protein/fiber, or insert a maintenance break.
Is a deficit the same every day?
Weekly average matters. Some people eat more on training days.
CTA
Calculate your cut with the calorie deficit calculator. Educational only — not medical advice. Seek professional care if you have a medical condition or disordered-eating history.