Grams to Calories Calculator

Convert macronutrient grams to calories and analyze nutritional composition

Macronutrient Input

g

4 calories per gram

g

4 calories per gram

g

9 calories per gram

Calorie Breakdown

Carbohydrates0%
0 kcal
from 0g
Protein0%
0 kcal
from 0g
Fat0%
0 kcal
from 0g
Total Calories0 kcal
from 0g total macronutrients

Common Food Examples

Apple (medium, 182g)

Carbs: 25g → 100 kcal
Protein: 0.5g → 2 kcal
Fat: 0.3g → 3 kcal
Total: 105 kcal

Chicken Breast (100g)

Carbs: 0g → 0 kcal
Protein: 31g → 124 kcal
Fat: 3.6g → 32 kcal
Total: 156 kcal

Avocado (100g)

Carbs: 9g → 36 kcal
Protein: 2g → 8 kcal
Fat: 15g → 135 kcal
Total: 179 kcal

Beer (12 oz, 5% ABV)

Carbs: 13g → 52 kcal
Protein: 2g → 8 kcal
Alcohol: 14g → 98 kcal
Total: 158 kcal

Calorie Content

Carbohydrates
Main energy source for the body
4 kcal/g
Protein
Building blocks for muscles and tissues
4 kcal/g
Fat
Energy-dense macronutrient for cell function
9 kcal/g
Alcohol
Provides energy but no essential nutrients
7 kcal/g

Nutrition Tips

Fat provides more than double the calories per gram compared to carbs and protein

Alcohol contains 7 calories per gram and provides no essential nutrients

Food labels show total calories and grams of each macronutrient

Understanding calorie sources helps with diet planning and weight management

Quick Reference

1g Carbs4 kcal
1g Protein4 kcal
1g Fat9 kcal
1g Alcohol7 kcal

Note: kcal = Calories on food labels

Understanding Macronutrients and Calories

What are Calories?

A calorie is a unit of energy. In nutrition, we typically use kilocalories (kcal), which are often simply called "calories" on food labels. One kilocalorie is the amount of energy needed to heat one kilogram of water by one degree Celsius.

Macronutrients Explained

  • Carbohydrates: The body's preferred energy source, found in fruits, grains, and vegetables
  • Protein: Essential for building and repairing tissues, found in meat, dairy, and legumes
  • Fat: Important for hormone production and vitamin absorption, found in oils and nuts

Practical Applications

Weight Management

Understanding calorie content helps you make informed decisions about portion sizes and food choices for maintaining, losing, or gaining weight.

Diet Planning

Knowing the calorie breakdown helps ensure balanced nutrition and appropriate macronutrient ratios for your health goals.

Food Label Reading

This calculator helps you verify the calorie information on food labels and understand how manufacturers calculate total calories.

Example Calculation

A food with 23g carbs, 4g protein, and 9g fat contains:

  • • Carbs: 23g × 4 = 92 kcal
  • • Protein: 4g × 4 = 16 kcal
  • • Fat: 9g × 9 = 81 kcal
  • • Total: 189 kcal