Energy from Food Components

Each macronutrient provides a different amount of energy per gram. Enter the grams of each component to calculate total energy.

Energy density per gram

Component	cal/g	kJ/g
Fat	9	37
Alcohol	7	29
Protein	4	17
Carbohydrates	4	17
Fibre	2	8

Calculate total energy

Enter the grams of each macronutrient in your food to see the total calorie breakdown.

Fat (g)

Alcohol (g)

Protein (g)

Carbohydrates (g)

Fibre (g)

Breakdown

Fat (10g × 9)90 cal(370 kJ)

Alcohol (0g × 7)0 cal(0 kJ)

Protein (25g × 4)100 cal(425 kJ)

Carbohydrates (50g × 4)200 cal(850 kJ)

Fibre (5g × 2)10 cal(40 kJ)

Total400 cal(1685 kJ)

Fat 23%Protein 25%Carbohydrates 50%Fibre 3%

About each component

Fat — 9 cal/g (37 kJ/g)

The most energy-dense macronutrient. Includes saturated, monounsaturated, and polyunsaturated fats. Essential for hormone production and nutrient absorption.

Alcohol — 7 cal/g (29 kJ/g)

Provides energy but no essential nutrients. The body prioritises metabolising alcohol over other macronutrients.

Protein — 4 cal/g (17 kJ/g)

Used primarily for muscle repair and growth. Has the highest thermic effect of food (~20-30% of protein calories are used in digestion).

Carbohydrates — 4 cal/g (17 kJ/g)

The body's preferred energy source, especially for the brain and high-intensity exercise. Includes sugars, starches, and fibre.

Fibre — 2 cal/g (8 kJ/g)

A type of carbohydrate that the body cannot fully digest. Provides roughly 2 cal/g on average due to partial fermentation in the colon.