Total calories in a meal, computed directly from its macronutrient breakdown rather than a single “total calories” figure entered by hand.
How it works
Each macronutrient’s grams are multiplied by its calorie-per-gram factor (4 for protein and carbohydrates, 9 for fat, 7 for alcohol) and summed.
What this does not include
This does not include dividing a total by servings — for that, use this site’s calories-per-serving calculator instead. This tool builds the total up from macronutrients.
How to use this calculator
- Enter the grams of protein, carbohydrates, fat, and alcohol (if any).
A worked example
30g protein, 50g carbs, 15g fat, 0g alcohol: calories = (30×4)+(50×4)+(15×9)+(0×7) = 455 calories.
0g protein, 0g carbs, 10g fat: calories = 90 — fat alone, at 9 calories per gram.
What the variables mean
| Variable | Meaning |
|---|---|
| Protein, carbs | 4 calories per gram each |
| Fat | 9 calories per gram — more than double protein or carbs |
| Alcohol | 7 calories per gram |
Edge cases worth knowing
Fat contributes more than double the calories of protein or carbs per gram — a meal heavy in fat can carry far more calories than its weight alone would suggest.
All four macros missing makes the total impossible to calculate — there’s no data to sum, so the calculator declines to show a result rather than assuming zero.
Frequently asked questions
Why does fat have a higher calorie-per-gram factor than protein or carbs?
Fat is a more energy-dense macronutrient — at 9 calories per gram, it holds more than twice the energy of protein or carbohydrates at 4 calories per gram each.
Are these the exact figures found on a nutrition label?
They’re the standard general factors nutrition labels are built on — the same figures used by the USDA’s FoodData Central database.
Why include alcohol as a fourth macronutrient?
Alcohol contributes meaningful calories (7 per gram) that aren’t protein, carbohydrate, or fat, so it’s tracked separately when calculating a meal or drink’s total calories.
