Before you argue about keto vs high-carb, get the one number that decides fat loss or gain: your daily calories. Everything else is a detail on top of it.
Step 1 — your BMR (Mifflin–St Jeor)
Basal metabolic rate is what you'd burn lying in bed all day. The Mifflin–St Jeor formula is the most accurate common one:
- Men: 10 × weight(kg) + 6.25 × height(cm) − 5 × age + 5
- Women: 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Step 2 — multiply by activity
| Activity | Multiplier |
|---|---|
| Sedentary (desk, little exercise) | 1.2 |
| Light (1–3 sessions/week) | 1.375 |
| Moderate (3–5 sessions/week) | 1.55 |
| Very active (6–7 sessions/week) | 1.725 |
BMR × multiplier = your maintenance calories (TDEE) — the number that keeps your weight stable.
Step 3 — set your target
- Fat loss: subtract 15–20% (about 300–500 kcal). Aim to lose ~0.5–1% of bodyweight per week.
- Muscle gain: add 5–10% (about 150–300 kcal). Slower is leaner.
- Recomp / maintenance: eat at maintenance and let training drive the change.
Step 4 — adjust with the scale, not the formula
The formula is a starting estimate, not gospel. Track your weight every morning, take the weekly average, and if it isn't moving the way you want after two weeks, nudge calories by ~150 and re-check. Your real intake and your trend beat any calculator.
Protein comes first
Whatever your calorie target, hit roughly 1.6–2.2 g of protein per kg of bodyweight. It protects muscle in a cut and builds it in a bulk — and it's the most filling macro, which makes the calorie target easier to hit.