Macro Split CalculatorCalculate optimal macronutrient distribution using evidence-based ratios. Determine precise protein, carbohydrate, and fat allocations for body recomposition, performance optimization, and metabolic health.
Input & Calculation
Daily Calories (TDEE)
Goal
0gProtein (0%)
0gCarbs (0%)
0gFat (0%)
1. How Macronutrients Affect Your Body
  • Protein (4 kcal/g)

    **Physiological Role:** Essential amino acid building blocks for muscle protein synthesis, enzymatic function, and hormonal regulation. **Metabolic Benefits:** Promotes muscle hypertrophy, enhances satiety through leptin signaling, and exhibits high thermic effect of food (TEF) requiring 20-30% of calories for digestion and metabolism.

  • Carbohydrates (4 kcal/g)

    **Physiological Role:** Primary substrate for anaerobic glycolysis and aerobic metabolism. Stored as muscle and hepatic glycogen (300-600g total capacity). **Performance Benefits:** Fuels high-intensity exercise, facilitates post-exercise glycogen resynthesis, maintains cognitive function, and supports protein-sparing during energy restriction.

  • Fats (9 kcal/g)

    **Physiological Role:** Structural component of cell membranes, precursor for steroid hormone synthesis (testosterone, estrogen, cortisol), and energy storage medium. **Metabolic Benefits:** Facilitates fat-soluble vitamin absorption (A, D, E, K), provides sustained energy through beta-oxidation, supports neurological function, and regulates inflammatory responses.

2. Rationale for Goal-Specific RatiosThe macronutrient distribution adjusts energy substrate availability to optimize specific physiological adaptations and metabolic outcomes based on training periodization and body composition goals:
Weight Loss (Cut)

High Protein (40%) ensures muscle preservation while in a calorie deficit. Fat is kept moderate (20%) for hormone health, and Carbs (40%) are high enough to provide energy for workouts.

Weight Gain (Bulk)

High Carbs (50%) maximizes training performance and muscle glycogen storage, which is crucial for muscle fullness and recovery. Protein is set high (30%) for growth, and Fat is kept moderate (20%) to manage overall calorie density.

3. The Calorie-to-Gram ConversionUnderstanding the energy density of each macro is how the calculator determines the gram amounts:
MacronutrientCalories per GramExample Calculation
Protein4 kcal / g(Total Calories × % Protein) ÷ 4
Carbohydrates4 kcal / g(Total Calories × % Carbs) ÷ 4
Fats9 kcal / g(Total Calories × % Fat) ÷ 9
4. Best Food Sources for Each Macro
🥩 Protein Sources
  • • Chicken breast (31g/100g)
  • • Eggs (13g/100g)
  • • Greek yogurt (10g/100g)
  • • Whey protein (80g/100g)
  • • Fish & seafood (20-25g/100g)
  • • Lentils (9g/100g)
🍚 Carb Sources
  • • Rice (28g/100g)
  • • Oats (66g/100g)
  • • Sweet potato (20g/100g)
  • • Banana (23g/100g)
  • • Quinoa (64g/100g)
  • • Whole wheat bread (43g/100g)
🥑 Fat Sources
  • • Avocado (15g/100g)
  • • Nuts & seeds (45-60g/100g)
  • • Olive oil (100g/100g)
  • • Salmon (13g/100g)
  • • Peanut butter (50g/100g)
  • • Coconut oil (100g/100g)
5. Meal Timing & Distribution Strategy
Protein Distribution - Aim for 20-40g protein per meal, spread evenly throughout the day. Post-workout: consume within 2 hours for optimal muscle protein synthesis.
Carb Timing - Pre-workout: 30-60g carbs 1-2 hours before training. Post-workout: 0.5-1g per kg body weight within 30 minutes for glycogen replenishment.
Fat Distribution - Spread throughout the day, but minimize 2 hours before/after workouts as fats slow digestion and nutrient absorption.
6. Common Macro Tracking Mistakes
❌ What NOT to Do
  • • Ignoring liquid calories (oils, drinks)
  • • Not weighing food (using cups/spoons)
  • • Forgetting to track condiments & sauces
  • • Being too rigid (80/20 rule works better)
  • • Copying someone else's macros
✅ Best Practices
  • • Use a food scale for accuracy
  • • Track everything for 2-3 weeks initially
  • • Focus on whole, minimally processed foods
  • • Adjust based on progress & energy levels
  • • Allow 10-15% flexibility for social events
⚠️ Clinical DisclaimerThese macronutrient calculations represent evidence-based estimates for general populations. Individual requirements may vary based on metabolic rate, training periodization, body composition, genetic polymorphisms, and medical conditions. Consult with a registered dietitian nutritionist or sports nutrition specialist for personalized nutritional programming.