Macro Calculator
Calculate daily protein, carb, and fat targets in grams based on your calorie goal and diet style.
About the Macros Calculator
Hitting a calorie target is only half the picture — how those calories split between protein, carbohydrates, and fat (your "macros") shapes satiety, muscle maintenance, and how a diet feels day to day. This calculator converts a calorie goal and diet style into specific gram targets for each macronutrient.
How It Works
The calculator applies a percentage split to your total calories based on the diet style chosen, then converts each macronutrient's calorie share into grams using its known energy density: protein and carbohydrates provide 4 calories per gram, while fat provides 9 calories per gram.
Protein (g) = (Calories × Protein%) / 4; Carbs (g) = (Calories × Carb%) / 4; Fat (g) = (Calories × Fat%) / 9.
Worked example
Scenario: A 2,200 kcal daily target on the balanced 30 / 40 / 30 split.
- Protein: 2,200 × 30% = 660 kcal ÷ 4 kcal/g = 165 g.
- Carbohydrates: 2,200 × 40% = 880 kcal ÷ 4 = 220 g.
- Fat: 2,200 × 30% = 660 kcal ÷ 9 = 73.3 g.
Result: About 165 g protein, 220 g carbs and 73 g fat a day.
Tips and common mistakes
- Get your calorie target from the Calorie Calculator first, then split it here.
- The low-carb preset is 40 / 20 / 40 and the high-protein preset is 40 / 35 / 25.
- Hitting protein and total calories matters more than matching carbs and fat exactly.
Assumptions & Limitations
- Uses standard energy densities of 4 kcal/g for protein and carbohydrates and 9 kcal/g for fat, which are the universally accepted conversion factors.
- Percentage splits are general presets — individual needs vary based on activity, goals, and personal preference.
- Does not account for fiber separately from total carbohydrates, or for individual medical dietary restrictions.
- A single macro split is a starting point; many people adjust it over time based on how they respond.
Macro targets are preferences, not diagnoses
The percentage presets on this calculator are convenient ways to divide a calorie budget; they are not universal medical recommendations. Two people with the same calorie target can reasonably use different macronutrient distributions depending on food preferences, training, health conditions and professional guidance.
The gram conversion itself is straightforward: protein and carbohydrate are calculated at 4 kcal per gram and fat at 9 kcal per gram. The important uncertainty is the chosen percentage split, not the arithmetic.
Sources and review
Method: Splits calories by the chosen percentages, then converts with 4 kcal/g for protein and carbohydrate and 9 kcal/g for fat (Atwater factors).
Sources:
- U.S. Department of Agriculture, energy values of macronutrients (Atwater general factors).
Last reviewed: October 2026 by Faheem Ali, founder of CalculatorAnything. The method and examples are provided for transparency; results remain estimates and may contain errors.
Results are estimates for general information and screening, not a diagnosis or medical advice. Talk to a qualified healthcare professional before making health or diet decisions. Spotted an error? Tell us — see our editorial policy for how corrections are handled.