The calories in food come from its macronutrients. Each gram of protein, carbohydrate, and fat contributes a fixed amount of energy.
Calories = (Protein × 4) + (Carbs × 4) + (Fat × 9)
Where
| Protein | grams of protein |
| Carbs | grams of carbohydrate |
| Fat | grams of fat |
Worked example
A food with 30 g protein, 40 g carbs, and 10 g fat has (30×4) + (40×4) + (10×9) = 120 + 160 + 90 = 370 calories.
Alcohol adds 7 calories per gram. Fat is the most energy-dense at 9 per gram, which is why high-fat foods are calorie-heavy for their size.
FAQ
Does this formula account for cooking losses like fat rendering out of meat? Not directly. It calculates calories from the ingredients as measured, so if fat renders out and is discarded during cooking, like draining ground beef, the finished dish typically has somewhat fewer calories than the raw ingredient total would suggest.
Estimate needs with the Calorie and TDEE calculator in the cooking calculators.