Macro Calculator
Split a calorie target you trust into protein, carbs, and fat.
Fill in the form and your result lands here.
Learn the details
I start from the TDEE you enter, holding it flat at maintenance and moving it 500 calories either way for a cut or a bulk. Protein is set first at 1g per pound of bodyweight for a cut or bulk and 0.75g per pound at maintenance, fat takes 25% of the calories, and carbs fill whatever is left.
Macros are how your daily calories get split into protein, fat, and carbs. Calories decide which direction your weight moves, and the split above has a lot to say about what you keep on the way there.
The energy math behind the split
Protein and carbs each carry 4 calories per gram. Fat carries 9. That one difference is why fat is taken as a share of your calories rather than a flat number of grams, and why moving that share a few points swings your carb number more than you would expect. Carbs land last on purpose. They are the flexible piece, the fuel you can push up on a heavy training day and pull back on a quiet one without cutting into your protein or dropping your fat too low.
Protein is the anchor
Protein gets claimed before anything else can eat into the budget, because it does the most work: it helps you hold onto muscle while losing fat, supports muscle growth while building, and keeps you fuller on fewer calories than fat or carbs do. That is also why the target rises when you are losing fat or gaining muscle and eases off at maintenance. The harder you are pushing your body in either direction, the more raw material it wants. Once protein is locked in, the rest of the day is just filling the remaining calories around it.
A worked example
Say your target lands at 2,200 calories a day and you weigh 180 pounds on a cut, so protein sits at 1 gram per pound: 180 grams, which is 720 calories. Fat takes around 25% of total calories, so 550 calories, which is about 61 grams. Add those up: 720 plus 550 is 1,270 calories spent, leaving 930 calories for carbs. Divide by 4 and carbs land around 233 grams. That is the whole calculator above, just walked through by hand.
Cutting, maintaining, and building
The calorie total is what moves between goals: a cut trims calories below maintenance, a bulk adds calories above it, and maintenance holds steady. Protein stays the anchor across all three, 1 gram per pound on a cut or bulk and 0.75 at maintenance, because it is protecting the same thing either way, your muscle, whether you are losing weight, holding it, or gaining. Fat and carbs simply reshuffle around whatever protein and the calorie target leave behind.
What to do with your split
If you do not have a calorie number yet, start with your TDEE so the macro split above is built on a real target instead of a guess. From there, check your protein target against what this calculator gave you, and if the goal is fat loss, the calorie deficit tool helps you set a pace you can actually sustain. For a full split worked through on a fat-loss target, see what macros to eat to lose fat. Hitting these numbers within 5 to 10 grams most days matters far more than hitting them exactly.
Sources: ISSN protein position stand
Hit protein first, then let fats and carbs fill in around it. Within 5-10g on each is close enough.