Macros for Muscle Gain: Lean Bulk Targets That Build Muscle, Not Just Fat

Building muscle has a reputation for requiring you to "eat big." The reality is more precise — and more flattering to your waistline. You need a small calorie surplus and enough protein, not a free-for-all. Get the macros right and you add muscle while staying lean enough to actually see it. Get them wrong and a "bulk" just becomes a slow fat gain. Here are the numbers that build muscle, not just bodyweight.

Muscle needs a surplus — a small one

Fat loss needs a deficit; muscle gain needs the opposite: slightly more energy than you burn, giving your body the raw material to build new tissue. The key word is slightly.

Find your maintenance with the TDEE Calculator, then add about 10% — roughly 250–350 calories. That's it. A bigger surplus won't build muscle faster (muscle growth is capped by your training and recovery, not by extra calories); it'll just add fat. The Lean Bulk Calculator sets this surplus precisely.

The lean-bulk macro split

In percentages this often lands near 30% protein / 45% carbs / 25% fat. Notice carbs are higher than in a fat-loss split — because here you want the training fuel and the anabolic edge that carbs provide.

A worked example

A 75kg lifter at maintenance of 2,500, bulking at +10% = 2,750 calories:

• Protein: 75 × 2.0 = 150g (600 cal)
• Fat: 75 × 0.9 = 68g (612 cal)
• Carbs: remaining 1,538 cal ÷ 4 = ~384g

Plug your own stats into the Macro Calculator and set the goal to muscle gain.

Protein: enough, not endless

Protein is the raw material, but more isn't better past a point. Aim for 1.6–2.2g per kg, spread across three or four meals so you're feeding muscle protein synthesis through the day. Beyond ~2.2g/kg there's no extra muscle benefit — those calories are better spent on carbs that fuel your training. Confirm your number with the Protein Calculator.

Don't fear the carbs

This is where lean bulking and fat loss genuinely differ. Carbs replenish the glycogen your muscles burn during heavy sets, power your hardest workouts, and help create the anabolic environment muscle growth thrives in. Keeping carbs high is a feature, not a cheat. Pair the nutrition with progressive overload — without the training stimulus, even perfect macros just add fat.

Lean bulk vs recomposition

If you're a beginner, returning after time off, or carrying higher body fat, you may not need a surplus at all — you can build muscle and lose fat at once (a recomposition). For most trained lifters, though, a small surplus is the faster, more reliable route. Choose lean bulk to maximise muscle; choose recomp to prioritise staying lean.

The takeaway

Muscle-gain macros are a small surplus, solid protein (1.6–2.2g/kg), and generous carbs to fuel the work. Resist the urge to eat big — patience and a controlled surplus build a physique you don't have to "cut" for months to reveal. Get your exact targets from the Macro Calculator.