Macro Calculator

Your goal changes the protein figure — not your calories. You've already chosen your calorie target; the goal just tells the tool how much protein to hold per kilogram while you're at that intake.

Cutting. Losing fat. Protein goes up per kg — it's most protective of muscle while calories are low. (2.2 g protein per kg bodyweight.)

Maintaining. Holding steady. A solid protein baseline with carbs filling the rest of your calories. (1.8 g protein per kg bodyweight.)

Bulking. Gaining. Protein eases slightly per kg — in a surplus carbs do more for training — so the extra calories mostly land as carbs to fuel your sessions. (1.6 g protein per kg bodyweight.)

Fat stays at the same grams-per-kilogram across goals, and carbs absorb the difference — so on a cut, with protein higher and calories lower, carbs are what give way, exactly as they should.

Under your result you'll see a line like “adds up to 2,598 kcal of your 2,600 target.” That gap is real, and it's honest on purpose. Grams are whole numbers, and four calories times a rounded gram count rarely lands exactly on your target — so the tool floors carbs rather than rounding them up past your budget. The result is usually a few calories left on the table, never a few over it.

This is deliberate. A macro calculator that always “added up perfectly” would be quietly fudging a gram here and there to hide the rounding. A handful of calories is well inside the margin of error of food labels and portion sizes, so we show you the real number instead of a tidy fiction.

Protein is set from your bodyweight — about 1.8 grams per kilogram at maintenance, easing to 1.6 g/kg on a bulk (in a surplus carbs do more for training) and rising to 2.2 g/kg on a cut, in line with the protein intakes shown to support resistance-trained lifters in the research literature. Fat starts at 0.8 g/kg with a hard floor of 0.6 g/kg: very low fat makes it hard to absorb fat-soluble vitamins and stick to the plan, and most guidance keeps fat at or above roughly 15–20% of calories, which is about 0.6 g/kg for most lifters. Carbs are the remainder: your calorie target minus protein and fat calories, divided by four and floored so the grams never claim more energy than your budget holds. Energy values are the standard 4/4/9 calories per gram for protein, carbs, and fat.

When the calorie target is too low to fit adequate protein, the fat floor, and a workable amount of carbs at your bodyweight, the tool does not fabricate a split. It reduces fat toward the floor to make room, and if carbs still can't reach a sensible minimum it flags the shortfall openly and shows the honest numbers — a signal that the calorie target itself is too low for your size, not a green light to eat that little.

The calculation runs entirely in your browser. The tool's own usage events only ever send coarse buckets — a bucketed calorie range, a bodyweight bracket, and your goal — never your exact numbers. If you use the share button, your entered values are encoded into that link so the page can rebuild your result; that link then sits in your address bar like any other URL. This is a fitness utility, not medical or dietary advice — protein, fat, and carb needs vary from person to person, and anyone with a medical condition should talk to a professional.