Free tool

Macronutrients Calculator

Calculate the grams of protein, carbohydrates and fat each client needs based on their goal. Define the diet with precision and adjust macros for deficit, maintenance or muscle gain.

Maintain weight

No calorie adjustment. Moderate-high protein (2.0g/kg) to maintain current body composition and perform well in training.

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How to calculate your daily macronutrient needs

Your daily macronutrient requirements depend on your total daily energy expenditure (TDEE) and your specific goal. This calculator uses the Mifflin-St Jeor equation to estimate your basal metabolic rate (BMR), then multiplies it by an activity factor to get your TDEE. From there, calories are adjusted for your goal and distributed across protein, fat and carbohydrates using evidence-based multipliers.

GoalCalorie adjustmentProtein target
Lose fat (deficit)−500 kcal/day2.2 g/kg
Maintain weightNo adjustment2.0 g/kg
Gain muscle (lean surplus)+300 kcal/day1.8 g/kg

Why protein and fat are set first

This calculator prioritizes protein and fat before assigning carbohydrates. Protein is essential for muscle retention and growth, while dietary fat is required for hormone production, vitamin absorption and brain function. A minimum of 0.9g of fat per kilogram of body weight ensures these processes are not compromised, regardless of the caloric goal.

Carbohydrates fill the remaining caloric space. They are the most flexible macro: not technically essential (unlike protein and fat), but highly beneficial for performance in high-intensity training. In a deficit, carbs decrease naturally; in a surplus, they increase to fuel muscle-building workouts.

Frequently asked questions