Macronutrient Calculator
Macronutrient targets tell you not just how many calories to eat, but how to distribute those calories between protein, carbohydrates, and fat to best support your specific goal. A standard balanced diet follows roughly 40% carbohydrate, 30% protein, and 30% fat. A weight loss approach may increase protein to preserve muscle while in a deficit. A muscle-gaining approach prioritises protein and carbohydrates to fuel training and recovery. A ketogenic approach dramatically cuts carbohydrates and raises fat to shift the body into ketosis. This calculator lets you enter your daily calorie target and choose a goal preset. It then divides those calories across the three macronutrients using goal-specific ratios and converts the calorie shares into grams per day, accounting for the different calorie densities of each macro: protein provides 4 kcal/g, carbohydrates provide 4 kcal/g, and fat provides 9 kcal/g. Use our BMR or Daily Calorie Needs Calculator to find your calorie target before entering it here.
Formula
Protein (g) = (Calories * protein%) / 4
Carbs (g) = (Calories * carbs%) / 4
Fat (g) = (Calories * fat%) / 9
Standard: 30% P / 40% C / 30% F
Weight loss: 40% P / 30% C / 30% F
Muscle gain: 30% P / 50% C / 20% F
Keto: 25% P / 5% C / 70% F
Macronutrient Calculator: frequently asked questions
What are macronutrients?
Macronutrients (macros) are the three main categories of nutrients that provide energy: protein (4 kcal/g), carbohydrates (4 kcal/g), and fat (9 kcal/g). Alcohol also provides energy (7 kcal/g) but is not a macronutrient. Getting the right balance of macros for your goals helps optimise energy, body composition, and performance.
What is the standard macronutrient ratio?
The Dietary Guidelines for Americans recommend that 45 to 65% of daily calories come from carbohydrates, 10 to 35% from protein, and 20 to 35% from fat. The standard ratio used in this calculator (40% carbs, 30% protein, 30% fat) falls within these ranges and is a commonly used balanced starting point.
What are macros for a ketogenic diet?
A ketogenic diet is very low in carbohydrates (typically under 50 g per day or around 5 to 10% of calories) and high in fat (70 to 75% of calories), with moderate protein (20 to 25% of calories). The very low carbohydrate intake induces ketosis, a metabolic state where the body burns fat for fuel. This calculator uses 5% carbs, 25% protein, and 70% fat for the keto preset.
How do I track my macros?
Food tracking apps allow you to log your meals and see how many grams of each macronutrient you have consumed versus your targets. Weighing food on a digital kitchen scale is the most accurate method. Many people use the hand-portion method as a lower-effort alternative: a palm of protein, a cupped hand of carbs, a thumb of fat, and a fist of vegetables per meal.
Should I change my macros over time?
Yes. As your weight, goals, or activity level changes, your calorie needs and optimal macro ratios may shift. If you are not seeing results after 3 to 4 weeks of consistent tracking, recalculate your calorie target from your current weight and consider adjusting ratios. A registered dietitian can provide personalised macro recommendations.
Official sources
- USDA: Dietary Guidelines for Americans 2020-2025
- National Academies: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (2005)
Reviewed by the CalculatorHub team, edited by James Graham, 14 June 2026. See our methodology.