How Many Calories Are In Fat, Carbs, And Protein? | Macro Math

Fat has 9 kcal/g, carbohydrates 4 kcal/g, and protein 4 kcal/g; alcohol adds 7 kcal/g when part of a meal.

How Many Calories Are In Fat, Carbs, And Protein: The 4-4-9 Rule Explained

Calories come from macronutrients. Protein and carbohydrates each provide 4 kilocalories per gram, and fat provides 9 kilocalories per gram. Those numbers are known as the Atwater general factors and they underpin how food databases and labels total up energy across foods and recipes. Alcohol isn’t a macronutrient you need for nutrition, yet it still contributes energy at 7 kilocalories per gram when it’s in the meal or drink.

That simple math helps you check portions and plan meals without memorizing dozens of items. If a snack has 10 grams of fat, you’re looking at 90 calories before counting the carbohydrate and protein. If a bowl of oats lists 40 grams of carbohydrate and 8 grams of protein, that’s 192 calories from those two macros alone, not counting any milk, oil, or nuts you might add.

Macro Calories Table

The chart below keeps the basics in one place so you can scan and move on.

Macronutrient Calories Per Gram What It Includes
Protein 4 kcal/g Meat, poultry, fish, eggs, dairy,