// Nutrition Calculators

Macro Calculator

Enter your details and goal to see your daily calories split into protein, carbs and fat.

Your details

Your result

Calories
2,633kcal/day
Protein
128g
Carbs
353g
Fat
79g
Protein range
105–150g
  • Protein is split at the midpoint of your 1.4–2 g/kg range so the three macros add up to one calorie total. Anywhere inside that range is a defensible target.
  • Fat is set at 27% of calories and carbohydrate takes the remainder.

Estimates are for general guidance only and are not medical advice. For a personalised plan, book a free guided tour at RPM Gym.

What your result means

The four numbers aren't independent. Calories come first, protein is set from your bodyweight, fat takes a share of the total, and carbohydrate gets what's left. Change the calorie target and all three move; change protein and only carbohydrate absorbs it.

Protein is anchored to bodyweight rather than to a percentage because that's how the evidence is expressed. You get a midpoint and the range it came from. The split has to use one number to make three figures add up, so it uses the middle — but anywhere inside that range is defensible, and the page shows you the range for exactly that reason.

Fat is set at 27% of calories, inside the commonly cited 20-35% band. It's high enough to cover the fat-soluble vitamins and the fatty acids you have to eat, and low enough to leave carbohydrate room to fuel training.

Carbohydrate is the remainder, and that's the honest description of it. It has no minimum requirement in the way protein and fat do, which makes it the flexible macro — the one you move when training volume changes or when a diet needs to become easier to live with.

How it is calculated

Shared calorie and protein models, with fat as a share of total energy

Calories = maintenance, or maintenance − 500 to lose, or a 10-20% surplus to gain Protein = bodyweight × 1.4-2.0 g/kg general · 1.6-2.2 g/kg gaining or in a deficit Fat = calories × 0.27 ÷ 9 Carbs = (calories − protein×4 − fat×9) ÷ 4

What it assumes

  • Protein is split at the midpoint of its range so the three macros reconstruct the calorie total exactly. The full range is printed beside it.
  • The 27% fat share sits inside the 20-35% of energy commonly recommended for adults. It's a starting split, not a requirement.
  • Atwater factors are used throughout: 4 kcal per gram of protein and carbohydrate, 9 per gram of fat. Fibre is counted as carbohydrate.
  • The calorie target inherits every limitation of the equation behind it, including a roughly ±10% error band on the maintenance estimate.

Units and rounding

  • Weight in kilograms, height in centimetres, age in years.
  • Macros in whole grams per day; calories in kilocalories per day.
  • Carbohydrate can go negative at very low calorie targets with a high bodyweight. That's the arithmetic telling you the target is too low, not a display bug.

Worked example

An 82 kg man, 180 cm, 30 years old, training four days a week, wanting to build muscle.

  1. Maintenance ≈ 2,916 kcal/day · gaining target = the middle of a 10-20% surplus = 3,209 kcal
  2. Protein = 82 × 1.6-2.2 = 131-180 g, midpoint 156 g → 624 kcal
  3. Fat = 3,209 × 0.27 ÷ 9 = 96 g → 866 kcal
  4. Carbs = (3,209 − 624 − 866) ÷ 4 = 430 g

3,209 kcal as 156 g protein, 430 g carbohydrate and 96 g fat. The 430 g of carbohydrate is what makes the training possible, and it's the number that changes first if he later decides to gain more slowly.

Limitations

  • Macro targets are less important than calorie totals for weight change, and less important than protein for body composition. Hitting carbs and fat to the gram buys very little.
  • The split doesn't know your training. A powerlifter and a marathon runner at the same weight and calories get identical numbers here, and they shouldn't.
  • It has no view on food quality. 430 g of carbohydrate from oats, rice and fruit is not the same day as 430 g from soft drinks, even though this page can't tell them apart.
  • Nothing here accounts for a medical condition or medication that changes how you handle carbohydrate or fat. Those change the answer and belong with a doctor or dietitian.
  • At aggressive deficits with a high bodyweight, protein and fat can crowd out carbohydrate almost entirely. If that happens, the deficit is the problem.

What to do next

  • Set protein first and treat it as the floor. It's the macro with the clearest body-composition evidence, and the easiest to fall short on when calories drop.
  • Then decide carbs and fat by how you train and eat rather than by the default split. Higher training volume usually wants more carbohydrate; if you find that split hard to stick to, move fat up and carbs down at the same calories.
  • Track for two weeks before adjusting anything. Most people discover their real intake differs from their intended one by more than any split change would.
  • If protein is the part you actually came for, the protein calculator goes deeper — including what changes when you're lean and dieting.

Sources

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// Frequently Asked

Questions, answered.

What are the best macros for fat loss?

The ones you can hold. Get calories into a deficit, keep protein at the upper end of its range to protect lean mass, then split the rest however you'll actually eat it. There's no carb-to-fat ratio with a consistent advantage once calories and protein are matched.

How many carbs should I eat per day?

Whatever's left after protein and fat, which for most people here lands somewhere between 200 and 450 g. Carbohydrate has no minimum requirement the way protein and fat do, so the honest answer is that it's set by your calorie target and how hard you train.

How much fat should I eat per day?

This page uses 27% of calories, which is inside the usual 20-35% range. Going much below about 20% starts squeezing the fat-soluble vitamins and essential fatty acids; going much above it takes room away from training fuel without a clear benefit.

Do I need to hit my macros exactly?

No. Within about 10 g of protein and fat, and whatever carbohydrate follows, is close enough for the result to be indistinguishable. Precision beyond that costs adherence and buys nothing measurable.

Why is protein shown as a range and a single number?

Because the requirement genuinely is a range, and the split needs one number to make the three macros add up to your calories. The single figure is the midpoint of the range printed beside it; anywhere inside that range is a reasonable target.

Should my macros change on rest days?

They can, but they don't need to. Weekly totals drive results, and cycling carbohydrate down on rest days mostly helps people who find it easier to eat more on training days. If that's not you, keeping every day the same is simpler and works.

Three numbers are easy to calculate and harder to eat.

Turning a macro split into meals you'll actually repeat is the part coaching is for. Start with a free guided tour at RPM Gym in Al Manhal.

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