Macro Split Calculator
Breaks your daily calorie goal into grams of protein, fat, and carbohydrates based on your chosen diet style — keto, low-carb, or balanced. Use it when starting a new diet plan or fine-tuning your nutrition for body composition goals.
About this calculator
Macronutrients — protein, fat, and carbohydrates — each provide a fixed number of calories per gram: protein 4 kcal/g, carbohydrates 4 kcal/g, and fat 9 kcal/g. This calculator divides your daily calorie target according to your diet type. For a balanced diet, carbohydrate grams = (dailyCalories × carb%) ÷ 4, where carb% = 100% − protein% − fat%. For a low-carb diet, carb% is fixed at 40% of remaining calories after protein. For keto, fat is fixed at 75% of total calories, so fat grams = (dailyCalories × 0.75) ÷ 9. Knowing your macro targets in grams — not just percentages — makes meal planning and food logging far more practical and precise.
How to use
Example: 2,000-calorie balanced diet, 30% protein, 30% fat. Step 1 — Protein: 2,000 × 0.30 ÷ 4 = 150 g. Step 2 — Fat: 2,000 × 0.30 ÷ 9 = 67 g. Step 3 — Carbs: remaining percentage = 100 − 30 − 30 = 40%, so 2,000 × 0.40 ÷ 4 = 200 g. Your daily targets are 150 g protein, 67 g fat, and 200 g carbohydrates. Cross-check: (150 × 4) + (67 × 9) + (200 × 4) = 600 + 603 + 800 ≈ 2,003 calories ✓.
Frequently asked questions
How do I calculate my macros for weight loss without losing muscle?
To preserve lean mass during a calorie deficit, protein intake is the most critical variable — most sports nutrition research recommends 0.7–1.0 g of protein per pound of body weight. After setting protein, fat should be kept high enough (≥20% of calories) to support hormone production and fat-soluble vitamin absorption. Remaining calories go to carbohydrates, which fuel exercise performance. Tracking your macros in grams rather than percentages ensures consistency even if your calorie target changes.
What is the best macro split for a ketogenic diet?
A standard ketogenic diet typically allocates around 70–75% of calories from fat, 20–25% from protein, and only 5% from carbohydrates — usually under 50 g of net carbs per day. This extreme fat intake shifts the body into ketosis, where it burns fat for fuel instead of glucose. The fat gram target is high — on 2,000 calories, that is roughly 167 g of fat per day — so food choices must be very intentional. Keto is not universally superior for fat loss but works well for people who prefer fewer, more satiating meals.
Why do macros matter more than just counting calories for body composition?
Total calories determine whether you gain or lose weight, but macronutrient composition determines what you gain or lose. Adequate protein signals muscle protein synthesis and reduces muscle catabolism during a deficit. Fat is required for hormone regulation, including testosterone and estrogen, which directly affect body composition. Carbohydrates modulate insulin and replenish muscle glycogen, supporting workout intensity and recovery. Getting the macro ratio right means you lose more fat and retain more muscle compared with simply eating less.