Enter how much protein, carbohydrate and fat you eat to estimate the calories your body burns digesting it (TEF).
Last updated: November 8, 2026
The digestion cost of each macronutrient
The thermic effect of food (TEF) is the energy you spend digesting, absorbing and storing what you eat. It makes up roughly 10% of the calories you burn in a day. Each macronutrient costs a different share of its own calories: • Protein: 20–30% • Carbohydrates: 5–10% • Fat: 0–3% The main result uses the middle of each range (25%, 7.5%, 1.5%). Calories: 4 kcal per gram of protein or carbs, 9 kcal per gram of fat. Example: 100 g protein (400 kcal), 250 g carbs (1,000 kcal) and 70 g fat (630 kcal) add up to 2,030 kcal. TEF = 400 × 0.25 + 1,000 × 0.075 + 630 × 0.015 ≈ 184 kcal, about 9% of the intake. The real value depends on meal size, how processed the food is and the person. Alcohol also has a thermic effect of about 10–30%, but it is not part of this calculation.
Common questions about the thermic effect of food
The calories your body uses to digest and process food. Together with your basal metabolic rate and movement, it is one of the three parts of daily energy use.
Other tools you may find useful
Grams you eat per day.
Grams you eat per day.
Grams you eat per day.