Macronutrient Calculator — Protein, Carbs & Fat Split
From TDEE and goal (maintain / cut / bulk), get daily grams of protein, carbs and fat.
Input Data
Results
Macronutrient calorie distribution
Daily grams by protein strategy
At a glance:Macronutrients are the three nutrients needed in large amounts: protein (4 kcal/g), carbohydrate (4 kcal/g) and fat (9 kcal/g). The calculator estimates BMR via Mifflin-St Jeor, multiplies by activity for TDEE, then converts target calories into daily grams using AMDR splits.
Formula
BMR (Mifflin-St Jeor): male = 10×weight + 6.25×height(cm) − 5×age + 5; female = 10×weight + 6.25×height(cm) − 5×age − 161.
TDEE = BMR × activity factor (1.2 sedentary to 1.9 very high).
Target = TDEE + goal (−500 lose / +300 gain).
protein(g) = target × protein% ÷ 4; carbs(g) = target × carbs% ÷ 4; fat(g) = target × fat% ÷ 9.
$$P_{g} = \frac{E \times p}{4},\quad C_{g} = \frac{E \times c}{4},\quad F_{g} = \frac{E \times f}{9}$$How to Use
- Enter sex, age, height and weight.
- Choose weekly activity and weight goal.
- Pick a protein strategy (standard / athlete / low-carb).
- The tool shows target calories and daily grams of each macronutrient.
Case Studies
Maintain (standard)
30yo male, 170 cm, 65 kg, moderate activity: BMR ≈ 1,568 kcal, TDEE ≈ 2,430 kcal.
Target 2,430 kcal → protein 122 g, carbs 304 g, fat 81 g.
Cut goal
Same but lose: target 1,930 kcal (−500).
Standard → protein 97 g, carbs 241 g, fat 64 g; switch to athlete and protein rises to 145 g, helping preserve muscle.
Bulk goal
25yo female, 160 cm, 50 kg, high activity: BMR ≈ 1,267, TDEE ≈ 2,185.
Bulk 2,485 kcal → protein 124 g, carbs 280 g, fat 69 g.
FAQ
How much protein do I need daily?
Most adults need ~0.8–1.0 g/kg; regular exercisers or those gaining muscle should aim 1.6–2.2 g/kg. Keep protein at 10–35% of calories (AMDR).
How do I adjust macros when cutting?
Create a ~500 kcal/day deficit and raise protein (~30%) to preserve muscle; protein also increases satiety, helping control intake.
Is low-carb for everyone?
Low-carb puts carbs at ~25%, near the low end of AMDR. Not advised for pregnant people, diabetics, or high-performance athletes without supervision. Consult a doctor or dietitian first.
Why does fat have more calories per gram?
Fat provides 9 kcal/g vs 4 kcal/g for protein and carbs, so even a modest fat % means far fewer grams than carbs.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.