Macro Calculator: How to Split Protein, Carbs & Fat
TL;DR
- Order: BMR → TDEE → goal calories → set protein & fat (g/kg) → carbs fill the rest
- Protein: 1.6–2.2 g/kg · Fat: 0.8–1 g/kg · Carbs: remaining calories
- Energy: Protein 4 kcal/g · Carbs 4 kcal/g · Fat 9 kcal/g
- Tracking: a photo calorie app removes the friction of logging every meal
1) What are macros, and why calculate them?
“Macros” is short for macronutrients — protein, carbohydrate and fat. Counting calories tells you how much you ate; macros tell you what you ate. Two days at the same calories can have very different outcomes: one preserves muscle, the other loses it. The difference is the macro split. That is why anyone serious about fat loss, muscle gain, or body recomposition tracks macros, not just calories.
2) Calculate your macros, step by step
Step 1 — BMR (basal metabolic rate)
The energy you burn at rest. The Mifflin-St Jeor equation is one of the most accurate:
Women: BMR = 10 × weight(kg) + 6.25 × height(cm) − 5 × age − 161
Step 2 — TDEE (total daily energy expenditure)
| Activity level | Multiplier |
|---|---|
| Sedentary (desk job) | 1.2 |
| Lightly active (1–3 days/week) | 1.375 |
| Moderately active (3–5 days/week) | 1.55 |
| Very active (6–7 days/week) | 1.725 |
Step 3 — Adjust for your goal
| Goal | Adjustment |
|---|---|
| Fat loss (cut) | TDEE − 15% to 20% |
| Maintenance | TDEE (no change) |
| Muscle gain (lean bulk) | TDEE + 5% to 10% |
Step 4 — Set your macros
- Protein: 1.6–2.2 g/kg (key for keeping/building muscle) → 4 kcal per gram
- Fat: 0.8–1 g/kg (needed for hormones) → 9 kcal per gram
- Carbs: remaining calories ÷ 4 → your training fuel
3) Worked example: 70 kg, 168 cm, 30-year-old woman, moderately active, fat loss
| Step | Calculation | Result |
|---|---|---|
| BMR | 10×70 + 6.25×168 − 5×30 − 161 | ≈ 1,439 kcal |
| TDEE | 1,439 × 1.55 | ≈ 2,230 kcal |
| Goal (−18%) | 2,230 × 0.82 | ≈ 1,830 kcal |
| Protein | 70 × 2 g = 140 g → 140×4 | 560 kcal |
| Fat | 70 × 0.9 g = 63 g → 63×9 | 567 kcal |
| Carbs | (1,830 − 560 − 567) ÷ 4 | ≈ 176 g |
Daily target: 1,830 kcal · 140 g protein · 176 g carbs · 63 g fat. Use the FitCoach AI BMI calculator and in-app calorie estimator to run these numbers automatically.
Make Your Macros Count: No-Equipment Strength Circuit
Enough protein + these moves = keep muscle while you lose fat. 3 sets each.
🏠 Full-body strength (home)
Muscle-sparing compound moves. Rest 45–60 sec between sets.
FAQ
How do I calculate my macros?
BMR → TDEE → goal calories → fix protein and fat per kg → carbs fill the rest. The worked example above shows every step.
What macro split should I use?
There’s no single right ratio. A common start is 30/40/30, but the robust method is to set protein and fat by body weight and let carbs fill the remainder.
How many calories per gram?
Protein 4, carbs 4, fat 9 kcal.