Macro Nutrient Calculator

Calculate your optimal macronutrient ratios based on your body metrics, activity level, and fitness goals. This calculator helps you determine the right balance of protein, carbohydrates, and fats to support your health and fitness objectives.

How the Macro Nutrient Calculator Works

This calculator determines your optimal macronutrient intake through a multi-step process:

Step 1: Calculate Basal Metabolic Rate (BMR)

First, we calculate your BMR using the Mifflin-St Jeor Equation:

For men: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(y) + 5
For women: BMR = 10 × weight(kg) + 6.25 × height(cm) - 5 × age(y) - 161

Step 2: Determine Total Daily Energy Expenditure (TDEE)

Next, we multiply your BMR by an activity factor to get your TDEE:

TDEE = BMR × Activity Factor

Activity factors range from 1.2 (sedentary) to 1.9 (very active).

Step 3: Adjust Calories Based on Goal

Weight Loss: TDEE - 500 calories
Maintenance: TDEE
Weight Gain: TDEE + 500 calories

Step 4: Calculate Macronutrient Distribution

Finally, we distribute your calories among macronutrients based on your selected ratio:

Carbohydrate grams = (Total calories × Carb percentage) ÷ 4
Protein grams = (Total calories × Protein percentage) ÷ 4
Fat grams = (Total calories × Fat percentage) ÷ 9

Predefined Macro Ratios

  • Balanced: 40% carbs, 30% protein, 30% fat - Good for general health and moderate activity
  • Low Carb: 25% carbs, 40% protein, 35% fat - Suitable for weight loss while preserving muscle
  • Ketogenic: 5% carbs, 30% protein, 65% fat - For ketosis and fat adaptation
  • High Carb: 60% carbs, 25% protein, 15% fat - Ideal for endurance athletes
  • Custom: Set your own percentages based on specific needs

Remember that macronutrient needs can vary based on individual factors such as metabolism, body composition, specific health conditions, and training regimens. This calculator provides a starting point that you can adjust based on your results and how your body responds.