Macro Calculator

Calculate daily protein, carbohydrates, fat intake, and personalized macronutrient targets for your fitness goals.

Macro Calculator

Convert a daily calorie target into grams of protein, carbohydrate, and fat. Macronutrient targets make a calorie goal actionable, since food labels and tracking apps report macros in grams.

How macros are calculated

Each macronutrient supplies a known amount of energy per gram, based on the standard Atwater factors:

  • protein: 4 kcal per gram;
  • carbohydrate: 4 kcal per gram; and
  • fat: 9 kcal per gram.

Given a calorie target and a percentage split, the grams for each macro are:

grams = (calories x percentage) / kcal per gram

Common starting splits include 30/40/30 (protein/carbs/fat) for general fitness, higher-carbohydrate splits such as 25/50/25 for endurance training, and higher-protein splits for muscle building or dieting. Another common approach sets protein first at roughly 1.6 to 2.2 g per kilogram of body weight, fat at 20 to 35 percent of calories, and fills the remainder with carbohydrate.

Worked example

A daily target of 2200 kcal with a 30/40/30 split of protein, carbohydrate, and fat:

  • protein: 2200 x 0.30 = 660 kcal, and 660 / 4 = 165 g;
  • carbohydrate: 2200 x 0.40 = 880 kcal, and 880 / 4 = 220 g; and
  • fat: 2200 x 0.30 = 660 kcal, and 660 / 9 = 73 g (73.3 before rounding).

So the day's plan is roughly 165 g protein, 220 g carbohydrate, and 73 g fat, which adds back up to about 2200 kcal.

How to interpret your result

Macro targets are planning estimates, not requirements your body enforces gram by gram. The 4/4/9 energy values are averages across foods, label rounding introduces small errors, and individual needs vary with training volume, body composition, and goals. Total calories and adequate protein matter most for body-weight outcomes; the carbohydrate-to-fat balance is largely a matter of preference, performance, and adherence. Hitting each macro within about 5 to 10 grams of the target on most days is precise enough for nearly everyone.

Practical tips

  • Set your calorie target first, using an estimate of your total daily energy expenditure.
  • Anchor protein to body weight (about 1.6 to 2.2 g per kg for active adults) before splitting the rest.
  • Do not push fat below roughly 20 percent of calories for long periods, as fat supports hormone production and vitamin absorption.
  • Choose the split you can sustain; adherence beats a theoretically ideal ratio.
  • Fibre and micronutrients still matter, so build macros mostly from minimally processed foods.

Related calculators

Use the calorie calculator or TDEE calculator to set the calorie target that this tool splits into macros. The protein calculator focuses on protein needs by body weight, the meal calorie calculator totals individual meals, and the heart rate zone calculator helps plan training intensity.

This calculator does not replace personalised advice from a qualified healthcare or nutrition professional.

Frequently asked questions

How are macro grams calculated from calories?
Each macronutrient has a standard energy value: 4 kcal per gram for protein and carbohydrate and 9 kcal per gram for fat. The calculator multiplies your calorie target by each macro's percentage, then divides by that macro's kcal per gram to get daily grams.
What is a good macro split for beginners?
A 30/40/30 split of protein, carbohydrate, and fat is a common general-fitness starting point. Endurance athletes often shift toward more carbohydrate, while people dieting or building muscle often raise protein. Total calories and adequate protein matter more than the exact ratio.
How much protein do I need per day?
Common evidence-based guidance for active adults is roughly 1.6 to 2.2 grams per kilogram of body weight per day, with the higher end often used during a calorie deficit to help preserve muscle. The general minimum recommended dietary allowance is lower, at 0.8 g per kg, for sedentary adults.
Do I have to hit my macros exactly?
No. Landing within about 5 to 10 grams of each target on most days is precise enough, since food labels and the 4/4/9 energy values are themselves averages. Consistency across weeks matters far more than daily precision.
Can fat be set very low to allow more carbs?
Keeping fat below roughly 20 percent of calories for long periods is generally discouraged, because dietary fat supports hormone production and absorption of fat-soluble vitamins. Most guidelines place fat between about 20 and 35 percent of total calories.
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