Macro split for fat loss, muscle gain and maintenance

There is no single "correct" macro split — the protein, fat and carbohydrate ratio that works best depends on your goal. For fat loss, protein sits at the high end of the range (1.6–2.0 g/kg) for people who exercise regularly, with moderate fat and the rest in carbohydrate. For muscle gain, protein stays in the same range, fat covers 20–30% of calories, and carbohydrate absorbs the remainder. For maintenance, protein is lower (1.4–1.6 g/kg) and fat and carbohydrate split the rest by preference. Sedentary adults need less protein (the general RDA is 0.8 g/kg/day).

Why the ranges overlap across goals

Protein needs rise in a calorie deficit because the body is in a catabolic state and needs extra amino acids to preserve muscle. The same is true for muscle gain, but the driver is synthesis rather than preservation, and the upper end of the range is similar. For maintenance, there is no extra stress, so the protein floor is lower. These ranges apply to people who exercise regularly; sedentary adults need less (the general RDA is 0.8 g/kg/day).

Fat loss split

A typical fat-loss split keeps protein high (to protect lean mass), fat at about 20–25% of total calories (for hormone production), and the remaining calories from carbohydrate:

Muscle gain (bulking) split

For muscle gain, protein stays in the same 1.6–2.0 g/kg range, fat covers roughly 25–30% of calories (enough to support hormones), and the rest comes from carbohydrate to fuel training:

Maintenance split

At maintenance, protein can settle to 1.4–1.6 g/kg (the everyday range for weight stability), and fat and carbohydrate split the remainder by your preference. The total is whatever your TDEE calls for, with no deficit.

Using the calculators

The macro calculator applies 1.8 g/kg protein and 25% of calories from fat, filling the rest with carbohydrate. The bulking calculator adds a surplus to the same split for muscle gain. And the protein calculator lets you pick a protein target within the range for your goal before the rest is assigned.

For help sizing the calorie total those macros sit on, see the deficit-sizing guide and the protein guide.

Limitations

These ranges assume you are an otherwise healthy adult engaged in regular training. They do not apply to people with kidney disease, eating disorders, or metabolic conditions. The gram-per-kilogram numbers are rounded from sport-nutrition research; individual needs vary.

Formulas are estimates, not medical advice.

Sources

Use the calculator

Start with your TDEE, pick a macro split, and refine from your real-world weight trend over two to three weeks. The macro calculator does the math for you in one click.