Macro Split Calculator

About this calculator

This calculator converts a daily calorie target into grams of protein, carbohydrates and fat based on a chosen percentage split (for example the popular 40/30/30 or 30/40/30 splits). It uses the standard caloric values of each macronutrient — protein and carbohydrates each provide about 4 calories per gram, while fat provides about 9 calories per gram — so grams = (total calories × macro percentage) ÷ calories per gram for that macro.

Bodybuilders, dieters and anyone following a structured nutrition plan (keto, high-protein, balanced/flexible dieting) use macro splits to translate an abstract calorie goal into a concrete, trackable grocery and meal-prep target. Different goals call for different splits — higher protein for muscle retention during a cut, higher fat for ketogenic diets, higher carbs for endurance athletes — and this calculator lets you plug in any percentage combination to see exactly how many grams of each macro that implies.