Macro Calculator
Once you know your daily calories, the next step is splitting them across the three macronutrients — carbs, protein and fat. Enter your calories and a ratio to see the grams of each.
Your numbers
Result
- Carbsgrams/day
- 200
- Fatgrams/day
- 67
- Percentages add up toshould be 100%
- 100%
| Macronutrient | % of calories | Grams/day |
|---|---|---|
| Carbs (4 kcal/g) | 40% | 200 |
| Protein (4 kcal/g) | 30% | 150 |
| Fat (9 kcal/g) | 30% | 67 |
How calories become grams
Each macro has an energy density: carbs and protein have 4 kcal/g and fat has 9 kcal/g. Take each macro's share of the calories and divide by its value: on a 2,000 kcal diet with 30% protein, that is 2,000 × 0.30 ÷ 4 = 150 g of protein.
Common splits
A balanced default is 40/30/30 (carbs/protein/fat). Low-carb diets cut carbs and raise fat; muscle-gain plans push protein (1.6–2.2 g/kg of body weight) and carbs. The three should always add to 100% — the result flags it if they do not.
What to prioritize
Protein is usually the macro to anchor first: it protects muscle while losing fat and supports gaining it. Carbs fuel training; fat is essential for hormones. Beyond hitting protein, the exact carb/fat split is mostly preference — the ratio you can stick to beats the "perfect" one.
Informational and educational result. Not a substitute for professional advice.
Frequently asked questions
Sources
- Atwater factors — energy density of macronutrients
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