How the calculation works
Per 100 g: kcal per kg = kcal × 10. Per can, pouch, treat or cup: kcal per kg = kcal ÷ its weight in grams × 1,000
A worked example
An 85 g pouch with 70 kcal holds 70 ÷ 85 × 1,000 = 824 kcal/kg. A dry food with 380 kcal per 100 g holds 3,800 kcal/kg, so a gram of it carries more than four times the energy of the pouch.
Why kcal per kg
Prices are compared per kg, so the energy has to be per kg too. With both, the price per 1,000 kcal tells you what the energy in a food costs, whether it comes in a bag of kibble or a case of pouches.
Wet food is mostly water
Wet food is about three quarters water, so it carries 700–1,300 kcal per kg against 3,300–4,200 for dry food. Per kg wet food looks expensive; per 1,000 kcal it is usually more expensive still.
Common questions
What is ME?
Metabolisable energy: the energy a pet can actually use from the food, which is what labels state as calorie content. US labels give it per kg and per cup; European labels usually per 100 g.
Can I convert kJ?
Divide kilojoules by 4.184 to get kilocalories first: 1,590 kJ per 100 g is 380 kcal per 100 g, or 3,800 kcal per kg.
Method: arithmetic from the label values you enter. Reviewed .