Macro Calculator

Protein (g) = target × protein% ÷ 4 · Carbohydrate (g) = target × carb% ÷ 4 · Fat (g) = target × (100 − carb% − protein%) ÷ 9

target

Your daily calorie target (kcal)

carb %

Carbohydrate share of that target

protein %

Protein share of that target

fat %

Fat share, whatever is left once the other two are taken out

meals

How many times a day you eat, used to divide the daily grams

Use it when you already know roughly how much to eat and the open question is how to divide it up — the macronutrient percentages are the last thing to set, not the first. The four patterns in the table are the usual starting points: pick the one closest to what you are doing, type its two numbers in, and the grams appear. If you are running a ketogenic plan, either calculator will do: type 5 percent carbohydrate and 20 percent protein here and the grams match the keto page exactly, because a general tool has to be able to reproduce a specialised one.

1. 2,000 kcal, 50 percent carbohydrate and 20 percent protein, 3 meals a day

   1. Fat share: 100 − 50 − 20 = 30 percent
   2. Protein: 2000 × 0.20 = 400 kcal, and 400 ÷ 4 = 100 g
   3. Carbohydrate: 2000 × 0.50 = 1000 kcal, and 1000 ÷ 4 = 250 g
   4. Fat: 2000 × 0.30 = 600 kcal, and 600 ÷ 9 = 66.67, rounded to 67 g
   5. Per meal: 2000 ÷ 3 = 666.67 kcal and 100 ÷ 3, 67 ÷ 3, 250 ÷ 3 give 33, 22 and 83 g

   The per-meal figures are divided from the rounded daily figures, so they do not always multiply back exactly: 83 g three times is 249 g, one gram short of the 250 printed above. Dividing the unrounded values would make the page's own arithmetic disagree with itself, which is worse than a gram. The same applies to the 667 kcal per meal, which is 2000 ÷ 3 rounded up.

2. 2,400 kcal, 40 percent carbohydrate and 30 percent protein, 4 meals a day

   1. Fat share: 100 − 40 − 30 = 30 percent
   2. Protein: 2400 × 0.30 = 720 kcal, and 720 ÷ 4 = 180 g
   3. Carbohydrate: 2400 × 0.40 = 960 kcal, and 960 ÷ 4 = 240 g
   4. Fat: 2400 × 0.30 = 720 kcal, and 720 ÷ 9 = 80 g
   5. Per meal: 2400 ÷ 4 = 600 kcal and 180 / 240 / 80 ÷ 4 give 45, 60 and 20 g

   Every figure divides cleanly here, which is what makes this case worth printing next to the previous one: 45 g of protein four times is exactly the 180 g above, so the arithmetic closes. Nothing else changes — the same two percentages on the same target give the same daily grams whatever the meal count, and only the per-meal row moves.

The percentages you can enter span 5 to 75 percent carbohydrate and 5 to 50 percent protein, with fat derived from whatever is left and never allowed below 10 percent. That range deliberately includes the bands dietary advice gives for the general population (45 to 65 percent carbohydrate, 20 to 35 percent fat, 10 to 35 percent protein) at both ends, which is why the page does not pass judgement on what you type: a page that can express a ketogenic split and a high-carbohydrate one has no business calling either of them a failure. Nothing here accounts for what the macronutrients are made of: 250 g of carbohydrate from white rice and from lentils behave differently in the body even though the number is identical, and 30 percent fat from olive oil is not the same diet as 30 percent from butter. Protein sufficiency in particular is not something a percentage settles, because the requirement scales with body weight and activity rather than with energy intake — the protein calculator on this site takes those two, and a 20 percent share can be well short of the requirement for a heavy person eating little. What the table's patterns describe is convention rather than any body's published recommendation: they are the splits people actually use, written as percentages so that they can be typed into the fields above.

What is a good macronutrient split?

Dietary advice for the general population gives carbohydrate 45 to 65 percent of energy, fat 20 to 35 percent and protein 10 to 35 percent, which leaves a lot of room inside it. Where you sit is decided by what the plan has to do — fuelling long training sessions, keeping protein high while eating less, or simply being sustainable for years. The tool prints the grams for the split you choose and does not rank it, because the same split is a good one for one person and a poor one for another.

How many grams of protein carbs and fat should I eat a day?

Divide your calorie target by share, then by the energy each gram supplies: about 4 kcal per gram for protein and carbohydrate, about 9 for fat. On a 2,000 kcal target with 50 percent carbohydrate and 20 percent protein, that is 250 g of carbohydrate and 100 g of protein, and the 30 percent left over is 67 g of fat.

Why does this page have no grade or badge?

Because the range of inputs deliberately includes the bands a grade would judge you against. The carbohydrate share can be set as low as 5 percent, which is a ketogenic plan, and as high as 75 percent, which is an endurance one; marking either as a failure would turn a page about how to divide energy into a page about not meeting a target. Three other pages on this site do judge something specific — whether protein clears its floor, whether saturated fat stays under its line — and each of those has a criterion that holds across its whole input range.

How is this different from the keto calculator?

The keto one asks you to pick from three fixed splits and adds a protein floor that scales with your body weight and activity. This one lets you type any percentages you like and adds the per-meal breakdown instead. Type 5 percent carbohydrate and 20 percent protein here and you get exactly the grams the keto page gives for its classic split — that is by design, since a general tool that cannot reproduce a specialised one is not general, it is just different.

Does meal frequency change anything?

Not the daily grams, and that is the honest answer. How many grams per meal you eat is arithmetic once the daily total and the meal count are fixed, and the evidence on spreading the same intake across more or fewer meals is thin for most outcomes. What the row is good for is planning: 180 g of protein is difficult to picture, and 45 g four times is a plate. If you train fasted or eat one large meal a day, the daily totals are still the numbers that matter.

Why do the per-meal numbers not add back up to the daily ones?

Because the per-meal figures are divided from the rounded daily figures rather than from the raw ones, so 83 g three times comes to 249 g against the 250 g printed above. The alternative would be per-meal numbers that do not match the daily number on the same screen, which readers would reasonably read as a bug. The gap is at most one gram per macronutrient and comes from rounding, not from the arithmetic.

• Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids (Macronutrients) — Institute of Medicine — National Academies Press, 2005
• Nutrition and Athletic Performance — joint position statement — Academy of Nutrition and Dietetics, Dietitians of Canada and American College of Sports Medicine, 2016
• Healthy diet — fact sheet — World Health Organization