Macro Split Calculator Formula

Understand the math behind the macro split calculator. Each variable explained with a worked example.

Use the Macro Split Calculator

Formulas Used

Protein

protein_g = round(daily_calories * protein_pct / 100 / 4)

Fat

fat_g = round(daily_calories * fat_pct / 100 / 9)

Carbohydrates

carb_g = round(daily_calories * carb_pct / 100 / 4)

Macro Total %

total_check = protein_pct + fat_pct + carb_pct

Variables

VariableDescriptionDefault
daily_caloriesDaily Calories(kcal)2500
protein_pctProtein %(%)30
fat_pctFat %(%)30
carb_pctCarb %(%)40

How It Works

How Macro Splits Are Calculated

Formula

  • Protein (g) = Calories x Protein% / 4 (4 cal per gram)
  • Fat (g) = Calories x Fat% / 9 (9 cal per gram)
  • Carbs (g) = Calories x Carb% / 4 (4 cal per gram)

    • Common Splits

  • Balanced: 30/30/40 (protein/fat/carbs)
  • High protein: 40/25/35
  • Low carb: 35/40/25
  • High carb (endurance): 25/20/55

    • Ensure percentages sum to 100%.

    Worked Example

    2500 kcal with a 30/30/40 split.

    daily_calories = 2500protein_pct = 30fat_pct = 30carb_pct = 40
    1. 01Protein = 2500 * 0.30 / 4 = 188 g
    2. 02Fat = 2500 * 0.30 / 9 = 83 g
    3. 03Carbs = 2500 * 0.40 / 4 = 250 g
    4. 04Check: 30 + 30 + 40 = 100%

    Ready to run the numbers?

    Open Macro Split Calculator