Macro split calculator
Calories decide whether you gain or lose. Macros decide what that change is made of. Give this your calorie budget, bodyweight, and goal — it hands back protein, carbs, and fat in grams, plus what that looks like per meal.
Your budget
Your macros
Protein is set at 0.8 g per lb of bodyweight (1 g on a cut), fat at 25% of calories, and carbs take the rest.
These are estimates, not medical advice — see the medical disclaimer.
The protein logic
Protein is set first because it is the macro with a job: building and keeping muscle. The research on lifters converges on roughly 0.7–1 g per lb of bodyweight — more than sedentary guidelines, and yes, that surprises people. We use 0.8 g/lb as the default and bump it to 1 g/lb on a cut, where the deficit makes muscle the thing most worth protecting.
Fat comes next at 25% of calories — enough for hormones without crowding out fuel. Carbs take every calorie that remains, because carbs are what hard training runs on.
Calories per gram
| Macro | kcal per gram | Role |
|---|---|---|
| Protein | 4 | Builds and keeps muscle |
| Carbohydrate | 4 | Fuels training and recovery |
| Fat | 9 | Hormones and satiety |
Honest caveats
Macros are a second-order tool: total calories and daily protein drive 90% of results, and the carb-fat ratio is mostly preference. Do not chase gram-perfect days — chase consistent weeks. And the split is only as good as the calorie number you feed it, so start with the TDEE calculator if you have not measured yours.
Common questions
Why 0.8–1 g of protein per pound?+−
Controlled studies on lifters cluster around 0.7–1 g per lb of bodyweight for maximizing muscle retention and growth. We default to 0.8 g and raise it to 1 g on a cut, when a calorie deficit puts muscle at risk.
Why is fat fixed at 25% of calories?+−
It covers hormone production and keeps food enjoyable while leaving enough calories for the carbs that fuel hard training. Anywhere in the 20–35% range works — 25% is a sane default to start from.
Do I need to hit these numbers exactly?+−
No. Land protein within about 10 g daily and let carbs and fat trade off with each other. The weekly calorie average decides fat loss or gain — one high-carb day changes nothing.
Should macros change on training vs rest days?+−
You can shift carbs toward training days if you like the structure, but total weekly intake is what moves results. Start with the same targets every day; add complexity only once the basics are automatic.
Macros set. Now the part nobody explains.
Getting the split right is step three of five. The Fuel Framework covers how to set the calorie number it starts from, what your sport actually changes, and how to adjust on evidence rather than guesswork.