Macronutrient Guide

Why Macros Matter

Three macronutrients provide all dietary calories: protein (4 kcal/g), carbohydrate (4 kcal/g), fat (9 kcal/g). Alcohol (7 kcal/g) is a fourth source. Different macros serve different roles: protein is mainly structural (muscle, organs, enzymes) — minimum 0.8 g/kg for sedentary adults, much higher for trained populations. Carbs are the primary fuel for higher-intensity exercise. Fat is essential for hormone production, vitamin absorption, cell membranes. Calorie balance determines whether you ga

Protein Targets by Goal

Sedentary adult RDA: 0.8 g/kg/day (preserve nitrogen balance, prevent deficiency). Real-world minimum for healthy active adult: 1.2-1.4 g/kg. Resistance training for muscle gain: 1.6-2.2 g/kg/day. Meta-analyses suggest 1.6 g/kg as a practical threshold beyond which additional protein adds little to muscle synthesis. Fat loss (preserving muscle in deficit): 1.8-2.4 g/kg. Higher protein particularly important when calorie-restricted to minimise muscle loss. Older adults (60+): 1.4-1.6 g/kg minimum

Carbohydrate Targets

Highly variable based on activity. Sedentary: 2-3 g/kg/day for general health (~150-200g for a 75kg adult). Mostly from vegetables, fruits, whole grains. Resistance training: 3-5 g/kg/day. Sufficient for glycogen replenishment between training sessions. Endurance training: 5-8 g/kg/day during heavy training blocks. Marathon training, cycling base building. Carb periodisation: vary intake daily to match training. Higher carbs on hard training days, lower on rest days. Helps body composition for e

Fat Intake

Minimum healthy intake: 0.5-0.8 g/kg/day (~40-60g for a 75kg adult). Below this risks hormonal disruption, especially female reproductive hormones, sex hormones in both sexes. Typical: 0.8-1.5 g/kg/day. Provides essential fatty acids and supports hormone function. Higher (1.5-3 g/kg): ketogenic or very-low-carb approaches. Quality matters: prioritise: olive oil, avocados, nuts, fatty fish (salmon, mackerel, sardines), eggs, full-fat dairy. Reduce: industrial seed oils (corn, soybean), trans fats

Not medical advice. This calculator is for general information and education only. Figures are estimates and may not reflect your circumstances. For decisions, consult your GP or a qualified healthcare professional. See our editorial standards.

Macronutrient Split Calculator (Protein, Carbs, Fat)

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