Same as meal calculator?
Yes—the math is identical; this page focuses on the 4-4-9 teaching angle.
Grams to Calories Calculator
Convert macro grams into calories using standard energy factors.
Grams to calories
Enter protein, carbohydrate, and fat grams.
About this calculator
How to use Grams to Calories Calculator, plus the formulas and logic behind the results.
Tool description
The 4-4-9 rule is the quick way dietitians and apps convert grams to calories for the three main macronutrients.
How to use
- Enter grams for each macro.
- Calculate per-macro and total calories.
- Use for recipes, labels, or macro tracking.
- Pair with Macro Calculator for daily targets.
Formulas & reference
Protein: 4 kcal/gCarbs: 4 kcal/gFat: 9 kcal/g
Quick math
- 100 g protein = 400 kcal
- 100 g carbs = 400 kcal
- 100 g fat = 900 kcal
Calculation logic
Straight multiplication and sum—same math as the Meal Calorie Calculator.
Sugar alcohols and fiber calories vary; this uses standard factors only.
Grams to Calories Calculator FAQ
Common questions about this calculator and how to use the results.
Net carbs?
Enter total carb grams unless you adjust manually for fiber.
Alcohol?
Use ~7 kcal/g separately—alcohol is not a macro here.
Rounding on labels?
FDA rounding can make label calories differ slightly from 4-4-9.
One macro only?
Leave others at zero if you are converting a single nutrient.
Kilojoules?
Multiply kcal by 4.184 for kJ if needed.