Macros Explained: Protein, Carbs and Fat Targets

"Macros" is short for macronutrients: protein, carbohydrate and fat, the three nutrients that supply nearly all of your calories. Counting calories tells you how much you eat. Macros describe what it is made of, which affects hunger, energy, training and how much muscle you keep when you lose weight. This guide explains how to turn a calorie target into grams, what the common splits look like, and what the official ranges say.

Calories per gram

Each macro gives a fixed number of calories per gram. Alcohol, not a nutrient we need, adds about 7 calories per gram.

From calories to grams, step by step

Start with your daily calorie target. Our calorie guide shows how to estimate it. Say it is 2,000 calories and you choose a 30% protein, 40% carbohydrate, 30% fat split.

1. Calories per macro: protein 2000 × 0.30 = 600, carbohydrate 2000 × 0.40 = 800, fat 2000 × 0.30 = 600.
2. Divide by calories per gram: protein 600 ÷ 4 = 150 g.
3. Carbohydrate 800 ÷ 4 = 200 g.
4. Fat 600 ÷ 9 = 67 g.

You can do this instantly with our Macro Calculator.

Common splits compared

No single split is right for everyone. Here are four common ones at 2,000 calories:

View the macro splits as numbers

Split	Protein	Carbohydrate	Fat
Balanced (30/40/30)	150 g	200 g	67 g
Low fat (30/55/15)	150 g	275 g	33 g
Low carb (40/20/40)	200 g	100 g	89 g
High protein (40/30/30)	200 g	150 g	67 g

Studies comparing diets with different macro ratios generally find that people lose similar amounts of weight when calories and protein are matched, and that the best split is the one a person can keep following. Choose by preference, health needs and how you feel.

What the official ranges say

• Protein: 10–35% of calories for adults, with a minimum RDA of 0.8 g per kg of body weight to avoid deficiency.
• Carbohydrate: 45–65% of calories, with a minimum of about 130 g a day to supply the brain.
• Fat: 20–35% of calories. Our Fat Intake Calculator uses this range and also shows saturated fat limits.

These are the Acceptable Macronutrient Distribution Ranges (AMDRs) set by the National Academies and used in the Dietary Guidelines for Americans. They are wide on purpose, because many mixes support health.

How much protein do you need?

Because protein affects muscle, a body-weight target is more useful than a percentage. The RDA of 0.8 g per kg is a floor that prevents deficiency. People who exercise regularly, are losing weight, or are older are often advised to eat more. Our Protein Calculator uses 1.0 to 1.8 g per kg for active people.

Very high protein intakes are not necessary for most people, and anyone with kidney disease or other medical conditions should talk to a doctor first.

Tips for using macros

• Set calories first, then protein, then split what remains between carbs and fat by preference.
• Be flexible. Hitting each number exactly every day is unnecessary. Weekly averages work.
• Count quality too. Fibre, vegetables and whole foods matter beyond the macro numbers.
• Adjust from results. If energy, hunger or progress is off after a few weeks, change one thing at a time.

Common questions

Sources and further reading

• National Academies: Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids
• Dietary Guidelines for Americans
• NHLBI: Calories and weight

This guide is for general education and is not medical or dietary advice. Needs vary with age, health and activity. Talk to a doctor or registered dietitian, especially if you have a medical condition.