Cutting Calorie Calculator
A cutting calorie calculator for estimating a calorie deficit. It applies your chosen percentage to estimated TDEE, displays the site’s 1.6–2.2 g/kg protein planning range, and flags targets below 1500 kcal/day. This alert does not determine whether a target is safe for an individual.
Result
| Estimated TDEE | |
| BMR (Mifflin-St Jeor) | |
| Activity multiplier | |
| Deficit | |
| Protein target | |
| Safety check |
Formula & source
Cutting target = TDEE × (1 − deficit%)
Protein planning range = 1.6–2.2 g per kg body weight
Site alert threshold: 1500 kcal/day (not an individual safety assessment)
Method and assumptions: Mifflin-St Jeor (1990) estimates resting energy use; this site applies a selected activity multiplier as a modeling assumption for TDEE. The combined estimate does not establish an individual accuracy range. The deficit is your planning input. The 1500 kcal/day alert is a site heuristic, not a validated individual minimum. The site uses 1.6–2.2 g/kg/day as a planning assumption. The ISSN 2017 position stand describes 1.4–2.0 g/kg/day for most exercising people and discusses higher intakes in specific training or energy-restriction contexts. Individual needs vary.
Worked example (you can verify by hand)
Input: same male (TDEE 2763), 20% deficit, 81.65 kg.
- Target = 2763 × 0.80 = 2210.4
- Protein = 130.6 to 179.6 g/day (unchanged — deficit comes from carbs/fat)
- Site alert: 2210 is above 1500; individual safety is not assessed
Expected output: ≈ 2210 kcal/day; protein 131–180 g/day.
Limitations — what this cannot do
- This is a planning estimate, not a measurement of your energy use. Resting-energy equations and selected activity factors do not establish a fixed personal error range; review the estimate against your own trend and circumstances.
- Activity multipliers are the largest error source; be honest about training volume or the number is fiction.
- This is nutrition math, not medical advice — see the disclaimer below.
- Very aggressive deficits cost muscle and adherence — a slower cut you finish beats a brutal one you quit.
- If you have a history of disordered eating, do not self-prescribe deficits — work with a professional.
Disclaimer: Estimates for training planning only, not medical advice. Consult a professional.
FAQ
How fast should I lose weight on a cut?
About 0.5–1% of body weight per week. Faster usually means meaningful muscle loss unless you are very overweight, where 1%+ can be fine.
Should protein stay high while cutting?
This calculator keeps the same 1.6–2.2 g/kg planning range when you change the deficit. It does not prescribe how to divide the remaining calories or assess your individual needs.
Do I need cardio to cut?
No — the deficit does the work and can come from diet alone. Cardio helps adherence and work capacity, but out-training a bad diet is a myth for most people.
When should I end the cut?
When you hit the goal, when strength has stalled for weeks, or when adherence collapses — whichever comes first. Then reverse-diet back up slowly.