What macros are and how grams are worked out
Macronutrients are the three sources of calories in food: carbohydrate and protein at 4 kcal per gram and fat at 9. A macro target splits a day's calories among them by percentage and converts each share to grams. On 2,200 kcal with a 50/25/25 split, carbohydrate is 2,200 × 0.5 ÷ 4 = 275 g, protein 138 g and fat 61 g. Fibre is a carbohydrate and alcohol (7 kcal/g) is none of the three.
The calculator gets the calorie figure either from your TDEE and goal or from a number you enter, then applies the split.
| Split | C/P/F % | Carbs | Protein | Fat |
|---|---|---|---|---|
| Balanced | 50/25/25 | 275 g | 138 g | 61 g |
| Low carb | 25/40/35 | 138 g | 220 g | 86 g |
| High protein | 40/40/20 | 220 g | 220 g | 49 g |
| Ketogenic | 5/25/70 | 28 g | 138 g | 171 g |
| Zone (40/30/30) | 40/30/30 | 220 g | 165 g | 73 g |
Choosing a split
For most people the split matters less than the calories and the protein. Research comparing low-fat and low-carbohydrate diets at equal calories finds similar fat loss; what differs is how full and how energetic people feel, which is personal. Rules of thumb: keep protein at 1.6–2.2 g per kg when losing weight or training hard (the high-protein and low-carb presets do this); keep fat at or above 20% of calories for hormone production and fat-soluble vitamins; and put the rest in carbohydrate scaled to your training — more for endurance and high-volume work, less if you are sedentary or prefer it.
| Macro | Acceptable range (% of calories) | Minimum | Energy |
|---|---|---|---|
| Carbohydrate | 45–65% | 130 g/day | 4 kcal |
| Protein | 10–35% | 0.8 g/kg (56 g men, 46 g women) | 4 kcal |
| Fat | 20–35% | None set; ≥ 20% for essential fatty acids | 9 kcal |
| Alcohol | — | — | 7 kcal |
Balanced split at different calorie levels
The same percentages give very different grams at different intakes, which is why a percentage-only plan can leave a small person short of protein. Check the protein grams against a per-kilogram target — the protein calculator gives one — and adjust the split if needed.
| Calories | Carbs | Protein | Fat |
|---|---|---|---|
| 1,500 kcal | 188 g | 94 g | 42 g |
| 1,800 kcal | 225 g | 112 g | 50 g |
| 2,000 kcal | 250 g | 125 g | 56 g |
| 2,200 kcal | 275 g | 138 g | 61 g |
| 2,500 kcal | 312 g | 156 g | 69 g |
| 3,000 kcal | 375 g | 188 g | 83 g |
Spreading macros across meals
Dividing protein evenly across meals — roughly 0.4 g per kg per meal, three to five times a day — appears to support muscle protein synthesis slightly better than loading it into one meal, and it makes hitting the daily total easier. Carbohydrate is usefully placed around training; fat timing does not matter. The calculator's per-meal column divides each macro by the number of meals you choose.
| Meals | Carbs / meal | Protein / meal | Fat / meal |
|---|---|---|---|
| 3 | 92 g | 46 g | 20 g |
| 4 | 69 g | 34 g | 15 g |
| 5 | 55 g | 28 g | 12 g |
| 6 | 46 g | 23 g | 10 g |
Keto and very-low-carb splits
A ketogenic diet keeps carbohydrate under about 50 g a day (often 20–30 g net of fibre), with fat supplying most calories and protein moderate. The keto preset uses 5/25/70. At 2,200 kcal that is 28 g of carbohydrate, 138 g protein and 171 g fat. Track net carbs (total minus fibre) if that is how your plan counts them; the calculator reports total carbohydrate.
Tracking and adjusting
Macros are usually tracked by weighing food and logging it; nutrition labels and databases give grams per serving. Aim to land within about 5–10 g of each target on average over the week rather than exactly each day. If weight is not moving as planned after two to three weeks, the calorie total — not the split — is the first thing to change; the TDEE calculator explains how much.
- Grams = calories × percentage ÷ kcal per gram (4, 4, 9).
- Protein first: 1.6–2.2 g/kg when dieting or training; the RDA minimum is 0.8 g/kg.
- Fat at 20–35% of calories; carbohydrate takes the remainder.
- Adjust calories for results, the split for preference.