The three macronutrients
Protein is found in meat, poultry, seafood, eggs, dairy, beans, peas, lentils, nuts, seeds and soy. Your body uses it to build and repair tissues, including muscle.
Carbohydrates include sugars, starches and fiber. They're found in grains, fruits, vegetables, beans and dairy, as well as in sweets and sugary drinks. Carbs are a main source of energy.
Fat is in oils, butter, nuts, seeds, avocados, fish, meat and dairy. It supplies energy, helps you absorb some vitamins, and provides essential fatty acids your body can't make.
Vitamins and minerals, by contrast, are micronutrients: you need them in tiny amounts and they supply no calories.
Calories per gram
Each macronutrient provides a set number of calories per gram:
| Macro | Calories per gram |
|---|---|
| Protein | 4 |
| Carbohydrate | 4 |
| Fat | 9 |
| Alcohol (not a nutrient you need) | 7 |
That's why fat-rich foods are so energy-dense: a gram of fat has more than twice the calories of a gram of protein or carbohydrate. To total up the calories in any mix of grams, use the macronutrient calories calculator.
For example, a meal with 30 g of protein, 45 g of carbohydrate and 15 g of fat has 30 × 4 + 45 × 4 + 15 × 9 = 120 + 180 + 135 = 435 calories.
How much of each macro do you need?
The National Academies set Acceptable Macronutrient Distribution Ranges (AMDRs) for adults, as a share of total calories:
| Macro | Share of calories | On 2,000 calories |
|---|---|---|
| Carbohydrate | 45–65% | 225–325 g |
| Fat | 20–35% | 44–78 g |
| Protein | 10–35% | 50–175 g |
The gram figures come from the percentages: 45% of 2,000 calories is 900 calories, and 900 ÷ 4 = 225 g of carbohydrate; 20% is 400 calories, and 400 ÷ 9 = 44 g of fat. The ranges are wide on purpose, because many different eating patterns can be healthy.
The Dietary Guidelines for Americans, 2025–2030, add a protein target based on body weight: 1.2 to 1.6 grams per kilogram per day, adjusted for your calorie needs. They also say saturated fat should, in general, stay under 10% of calories, and that added sugars should be kept low, no more than 10 grams in a meal.
Quality matters as much as the numbers
Two days with identical macros can look very different. 250 grams of carbohydrate from vegetables, fruit, beans and whole grains is not the same as 250 grams from soda and candy. The Dietary Guidelines put the emphasis on nutrient-dense, minimally processed foods, fiber-rich whole grains, a variety of protein foods, and healthy fats, with limited highly processed foods and refined carbohydrates. See what is a balanced diet for the full picture.
How to work out your own macros
- Estimate your calories. The TDEE calculator estimates the calories you burn each day; the calorie calculator adds a gradual change if you want one.
- Set protein first. Multiply your weight in kilograms by a figure in the 1.2–1.6 range, or use the protein calculator.
- Split the rest between carbs and fat, staying within the ranges above. The macro calculator does this for common splits.
Example: someone eating 2,200 calories who weighs 75 kg sets protein at 1.4 g/kg: 105 g, or 420 calories. With fat at 30% of calories (660 calories, or 73 g), the remaining 2,200 − 420 − 660 = 1,120 calories come from carbohydrate: 280 g, which is about 51% of calories, inside the 45–65% range.
Do you need to count macros?
Most people don't. Counting can be useful for a while, to learn what's in your food, or for specific sports goals. But eating a variety of whole foods in sensible portions gets most people into healthy ranges without tracking. If tracking food starts to feel stressful or obsessive, it's a good idea to stop and talk with a doctor or a registered dietitian.
Sources
- NIDDK health dictionary: calorie — 4 calories per gram of carbohydrate and protein, 9 for fat, 7 for alcohol.
- National Academies: Rethinking the Acceptable Macronutrient Distribution Range (2024), chapter on current AMDRs — carbohydrate 45–65%, fat 20–35%, protein 10–35% of calories.
- USDA and HHS: Dietary Guidelines for Americans, 2025–2030 (January 2026)
- MedlinePlus (NIH): Dietary fats explained