Meal Calories Calculator
Estimate a meal's total calories and the calorie share of the three macronutrients from grams of protein, carbs, and fat.
Input Data
Results
At a glance:Estimate a meal's total calories and the calorie share of the three macronutrients from grams of protein, carbs, and fat.
Formula
Total calories = protein × 4 + carbs × 4 + fat × 9 (Atwater factors).
Share = each macro's kcal ÷ total kcal.
How to Use
- Enter the grams of protein, carbs, and fat in the meal.
- The calculator returns total calories and the calorie share of each macro.
FAQ
Is the factor accurate?
Atwater is a general approximation; fibre and sugar alcohols cause deviation.
How is it different from macros-calculator?
macros-calculator derives macros from goals; this derives calories from macros — the reverse.
Alcohol?
This tool excludes alcohol calories; see alcohol-units.
Fibre?
Fibre is counted in carbs but is usually 2 kcal/g; this tool simplifies to 4.
Precision?
Integer kcal and percentages.
Related Tools
References
Content review: Calculatorism Science Team. Results are for reference only; please refer to the relevant authorities for the official figures.