What are macronutrients (macros)?
Macronutrients are the three nutrients that provide energy (calories) to your body:
| Macro | Calories/g | Main Function | Typical Sources |
|---|---|---|---|
| Carbohydrates | 4 kcal/g | Quick energy, brain fuel | Rice, pasta, bread, fruit, vegetables, legumes |
| Protein | 4 kcal/g | Tissue building/repair, enzymes, hormones | Meat, fish, eggs, dairy, tofu, legumes |
| Fat | 9 kcal/g | Dense energy, hormones, vitamin absorption | Olive oil, nuts, avocado, fatty fish |
Alcohol provides 7 kcal/g but is not an essential macronutrient and isn’t included in the split.
How this tool calculates your macros
1. Basal Metabolic Rate (BMR) — Mifflin-St Jeor
The Mifflin-St Jeor (1990) equation is the most validated for general population:
| Sex | Formula |
|---|---|
| Male | BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) + 5 |
| Female | BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(years) - 161 |
Alternative: Katch-McArdle uses body fat % (more accurate if known), but Mifflin-St Jeor is standard without that data.
2. Total Daily Energy Expenditure (TDEE)
TDEE = BMR × Activity Factor| Level | Factor | Description |
|---|---|---|
| Sedentary | 1.2 | Little/no exercise, desk job |
| Light | 1.375 | Light exercise 1-3 days/week |
| Moderate | 1.55 | Moderate exercise 3-5 days/week |
| Active | 1.725 | Hard exercise 6-7 days/week |
| Very Active | 1.9 | Training 2×/day, heavy physical job |
3. Goal → Target Calories
| Goal | Adjustment on TDEE |
|---|---|
| Maintain | TDEE (no change) |
| Lose weight | TDEE - 20% (min. -500 kcal) |
| Gain weight | TDEE + 15% (max. +300 kcal) |
| Custom | TDEE + kcal you specify (+/-) |
Note: A 500 kcal/day deficit ≈ 0.5 kg/week theoretical. Reality varies due to metabolic adaptation, NEAT, adherence, etc.
4. Split → Grams per macro
g_carbs = (target_calories × %carbs / 100) / 4
g_protein = (target_calories × %protein / 100) / 4
g_fat = (target_calories × %fat / 100) / 9Included Split Presets
| Preset | Carbs | Protein | Fat | For Whom |
|---|---|---|---|---|
| Balanced | 40% | 30% | 30% | General, maintenance, recomposition |
| High Protein | 40% | 40% | 20% | Fat loss preserving muscle, strength |
| Low Carb | 20% | 40% | 40% | Glycemic control, insulin sensitivity |
| Keto | 5% | 25% | 70% | Strict ketogenic diet (< 50g carbs/day) |
| Zone | 40% | 30% | 30% | Zone Diet (Sears), inflammation control |
You can customize any split. Percentages must sum to 100%.
Reference Ranges (ISSN, ACSM, EFSA)
| Population | Protein (g/kg/day) | Carbs (g/kg/day) | Fat (% kcal) |
|---|---|---|---|
| Sedentary | 0.8 - 1.0 | 3 - 5 | 20 - 35% |
| Recreational | 1.0 - 1.4 | 5 - 7 | 20 - 35% |
| Strength/power | 1.6 - 2.4 | 4 - 7 | 20 - 35% |
| Endurance | 1.2 - 2.0 | 6 - 10 | 20 - 35% |
| Keto adapted | 1.5 - 2.0 | < 1 (absolute) | 70 - 80% |
These are reference ranges. The calculator gives you a starting point; adjust based on real response (weight, measurements, energy, blood work).
Complete Example
Male, 30 years, 180 cm, 85 kg, moderate activity, goal lose, preset High Protein (40/40/20)
- BMR = 10×85 + 6.25×180 - 5×30 + 5 = 850 + 1125 - 150 + 5 = 1,830 kcal
- TDEE = 1,830 × 1.55 = 2,837 kcal
- Goal lose = 2,837 × 0.8 = 2,269 kcal (deficit ~568 kcal)
- Macros:
- Carbs: 2,269 × 0.40 / 4 = 227 g
- Protein: 2,269 × 0.40 / 4 = 227 g (2.67 g/kg — high, good for muscle retention)
- Fat: 2,269 × 0.20 / 9 = 50 g
Try the calculator now
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Calculate your macros and calories based on your goal and activity.