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Food Calorie Calculator

A food’s calories come from its macronutrients. Enter the grams of carbs, protein, fat and any alcohol to get the total calories and where they come from, using the Atwater factors.

Your numbers

g
g
g
g

Result

Total calories
415
kcal
From carbskcal
200
From proteinkcal
80
From fatkcal
135
Calories by macronutrient
MacronutrientCaloriesShare
Carbs (4 kcal/g)20048%
Protein (4 kcal/g)8019%
Fat (9 kcal/g)13533%
Alcohol (7 kcal/g)00%
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The Atwater factors

Each macronutrient supplies a set number of calories per gram: carbs and protein 4 kcal/g, fat 9 kcal/g, and alcohol 7 kcal/g. Total calories are the sum. For 50 g carbs, 20 g protein and 15 g fat: 50x4 + 20x4 + 15x9 = 200 + 80 + 135 = 415 kcal.

Why fat looks calorie-dense

Fat packs more than twice the calories of carbs or protein per gram, so a small amount adds up fast. That is why cooking oils and nuts are calorie-dense. Reading a label, you can check the math: multiply each macro by its factor and the totals should roughly match the stated calories.

Informational and educational result. Not a substitute for professional advice.

Frequently asked questions

Sources

  • Atwater general factors (energy per gram of macronutrient)

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