Macros Calculator (Protein, Carbs, Fat)

Each macro has a calorie density (Atwater general factors): protein 4 kcal/g, carbs 4 kcal/g, fat 9 kcal/g. So grams = (calories × percent ÷ 100) ÷ kcal-per-gram. A 2000 kcal day at 30% protein is 2000 × 0.30 ÷ 4 = 150 g protein.

Yes — within half a percentage point, to allow for harmless rounding (33/33/33 doesn't sum to exactly 100). If your numbers are off by more than 0.5, the calculator flags it so you don't end up under- or over-feeding.

There's no single right answer. Common starting points: 30/40/30 (P/C/F) for general health; 40/30/30 or higher protein for body recomposition; lower-carb plans go 25/30/45 or further. The right split depends on your goal, activity, and what you'll actually stick to.

In everyday food labelling, "calorie" usually means kilocalorie (kcal) — the energy to heat 1 kg of water by 1 °C. So "2000 calories" on a label = 2000 kcal = 2,000,000 small-c calories. Confusing, but universal.

Correct — it's the simple arithmetic. Talk to a registered dietitian or doctor for individual nutrition planning, especially if you have medical conditions, food allergies, or are pregnant / breastfeeding.