Macros for Muscle Gain — How to Set Your Targets in a Surplus

Building muscle needs two things working together: a calorie surplus (or at least not a deficit) and enough protein, distributed sensibly, to give your body the raw material for muscle repair and growth. Carbs and fat matter too, but mostly for supporting training performance and hormone function rather than driving the muscle-building process directly. Here’s how to set each one.

Step 1: Set Your Calorie Surplus

Muscle gain requires a calorie surplus — more energy in than out — though the size of that surplus matters less than consistency. A modest surplus of roughly 200–300 calories above maintenance is generally enough to support muscle growth while limiting excess fat gain, for most people training with a structured resistance program. Use our calorie calculator to find your maintenance number first.

Step 2: Set Protein Based on Body Weight

Research position stands from sports nutrition bodies generally support roughly 1.6–2.2 grams of protein per kilogram of body weight per day for building muscle, with most of the practical benefit reached by around 1.6 g/kg for most people — going higher provides diminishing additional benefit for most trainees. For a 75 kg (165 lb) person, that’s roughly 120–165 g of protein per day.

Step 3: Fill In Fat and Carbs

After protein is set, a reasonable starting split for the remaining calories is:

Carbs fill the rest of the calorie budget after protein and fat are set, since they’re the body’s preferred fuel for the higher-intensity training that drives muscle growth. Very low-carb approaches tend to make it harder to sustain training intensity, which can work against the goal.

A Worked Example

For a 75 kg person with a 2,700-calorie maintenance level, targeting a 300-calorie surplus (3,000 calories total), with protein at 1.8 g/kg:

• Protein: 135 g (540 calories)
• Fat: 25% of 3,000 calories = 83 g (750 calories)
• Carbohydrate: remaining 1,710 calories ÷ 4 = about 428 g