GIFSQ Tools · Module 1 — Food Composition & Proximate Analysis · Tool 12 of 500
Energy from the proximate values, with the Atwater general factors. Enter protein, fat, carbohydrate, fibre and alcohol to get energy in kcal and kJ.
Try sample values — fills the form with the worked example below.
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Energy (kcal / 100 g)
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Energy (kJ / 100 g)
Energy from fat (%)
Equation: Energy (kcal) = 4 × protein (g) + 9 × fat (g) + 4 × carbohydrate (g) + 2 × fibre (g) + 7 × alcohol (g)
Energy (kJ) = Energy (kcal) × 4.184.
Method: Atwater general factors, FAO Food and Nutrition Paper 77 (protein 4, fat 9, carbohydrate 4 kcal/g); fibre 2 kcal/g and the 4.184 kJ/kcal factor from Regulation (EU) No 1169/2011, Annex XV.
Assumptions: the Atwater factors are averages across mixed diets; carbohydrate here is total carbohydrate by difference, fibre counted at 2 kcal/g.
Limitations: the factors do not fit single foods with unusual composition (sugar alcohols, resistant starch, high-fibre foods) — those need specific factors; the result is metabolizable energy, not gross (bomb calorimeter) energy.
Rounding: results to 2 decimal places; intermediate values are not rounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Energy (kJ) = Energy (kcal) × 4.184.
Method: Atwater general factors, FAO Food and Nutrition Paper 77 (protein 4, fat 9, carbohydrate 4 kcal/g); fibre 2 kcal/g and the 4.184 kJ/kcal factor from Regulation (EU) No 1169/2011, Annex XV.
Assumptions: the Atwater factors are averages across mixed diets; carbohydrate here is total carbohydrate by difference, fibre counted at 2 kcal/g.
Limitations: the factors do not fit single foods with unusual composition (sugar alcohols, resistant starch, high-fibre foods) — those need specific factors; the result is metabolizable energy, not gross (bomb calorimeter) energy.
Rounding: results to 2 decimal places; intermediate values are not rounded.
This is a calculation aid, not a laboratory report — confirm against your accredited method before citing a value.
Worked example: Protein 10.00 g, fat 5.00 g, carbohydrate 70.00 g, fibre 3.00 g per 100 g. Energy = 4 × 10 + 9 × 5 + 4 × 70 + 2 × 3 = 40 + 45 + 280 + 6 = 371.00 kcal; in kJ, 371 × 4.184 = 1552.26 kJ; energy from fat = 45 ÷ 371 × 100 = 12.13 %.
Enter values above to see results.
Reference: protein 4, fat 9, carbohydrate 4, fibre 2, alcohol 7 kcal per gram. A food with 0 g of every nutrient has 0 kcal — check the inputs if that is not what you expect. Tool 12 of 500 — GIFSQ
