Macros are the second decision, not the first
Macronutrients — protein, carbohydrate and fat — are the three things in food that carry energy. Your calorie total decides the direction your weight moves. Your macro split decides what that change is made of, and how you feel while it happens. That order matters: a perfect 40/30/30 split at 3,000 kcal will not make you leaner if you maintain on 2,400.
So the honest sequence is: set calories with a TDEE calculator or the calorie calculator, then split those calories here. Everything below assumes you already have a number you trust.
The arithmetic: 4, 4 and 9
Every macro split is just a division problem, because each macro has a fixed energy density:
Fat being 9 kcal per gram is why fat grams always look small next to carb grams. On the donut above, a 30% fat slice is the same size as a 30% carb slice, but it is barely half the grams. Alcohol, for completeness, is 7 kcal per gram and belongs to no macro — which is why it quietly wrecks otherwise tidy tracking.
The presets, and who each one is for
| Preset | P / C / F | Use it when |
|---|---|---|
| Balanced | 30 / 40 / 30 | Maintaining, general training, no strong preference |
| Cutting | 40 / 30 / 30 | In a deficit — high protein for muscle and satiety |
| Bulking | 30 / 45 / 25 | Small surplus, hard training, carbs as fuel |
| Low-carb | 35 / 20 / 45 | You prefer eating this way, or appetite control is the problem |
| Keto | 25 / 5 / 70 | Deliberately staying in ketosis; accept lower peak output |
These are starting shapes, not laws. The two things worth protecting are enough protein and enough fat for hormone production (roughly 0.5 g/kg of body weight as a floor — see the fat intake calculator). Between those two floors, the split is yours.
Set protein first, then let carbs and fat argue
Protein is the only macro with a hard requirement tied to your body rather than your calories. It is the most satiating of the three, has the highest thermic cost (20–30% of its calories are spent digesting it), and is the difference between losing fat and losing muscle in a deficit. Anchor it in grams per kilogram of body weight — typically 1.6–2.2 g/kg if you train — and only then convert to a percentage. Our protein calculator gives the number for your weight and goal.
Carbohydrate is next, and it is a training decision more than a health decision. If you train hard or long, carbs are the fuel that lets you do it again tomorrow; the carbohydrate calculator sets that by training volume in g/kg. Fat then takes whatever is left — with the caveat that it cannot go too low, because it carries fat-soluble vitamins and the raw material for sex hormones.
Spread protein across the day
Total daily protein does most of the work, but distribution helps at the margin. Roughly 0.4 g/kg per meal across three to five meals maximises the muscle-protein synthesis response each time you eat, rather than dumping most of your protein into dinner. The per-meal table above splits your targets evenly for 3, 4 or 5 meals — treat it as a template, not a schedule.
Fibre: the number inside your carb number
Fibre is a carbohydrate, so it lives inside your carb target rather than beside it. The standard reference intake is 14 g per 1,000 kcal — about 34 g at 2,400 kcal — and most people eat roughly half that. It matters here because two diets with identical macros can behave completely differently: 240 g of carbs from oats, beans, fruit and vegetables leaves you full, while 240 g from white bread and sweets leaves you hungry an hour later. Macros describe the accounting. Food choice decides whether the accounting is pleasant.
How to use the numbers without becoming a spreadsheet
Track for two to three weeks to learn what your usual meals actually contain, then stop measuring and start recognising. Most people converge on ten or fifteen meals they rotate; once you know the macros of those, you can hit targets by choosing meals instead of weighing food. Recheck when your weight has moved by 3–4 kg, when training volume changes materially, or when the scale trend stops matching your goal for three weeks straight.
And if the numbers ever conflict with adherence, adherence wins. A 30/40/30 split you follow beats a 40/30/30 split you abandon on Thursday.