Pet food calories and dry matter

Read protein, fat, fiber, ash and moisture from the label. Carbohydrates are calculated by difference (100 minus everything else), and energy with the NRC 2006 method recommended by the FEDIAF guidelines. The calculator does this for you and also shows the result from the simpler modified Atwater formula.

EU Regulation 767/2009 requires protein, fat, fiber and ash on the label, but not energy, and moisture only when it is above 14%. That is why many bags of dry food sold in Europe show neither calories nor moisture. In the US, AAFCO rules do require a calorie statement.

It is the composition of the food with the water taken out. Wet food is about 75 to 80% water, so 10% protein on a can label is about 45% on a dry matter basis. Only dry matter or per-1000-kcal figures let you compare dry and wet food fairly.

Under the 2025 FEDIAF guidelines, food for adult dogs should have at least 18 to 21 g of protein per 100 g of dry matter (more for less active dogs, which eat less), and puppy food 20 to 25 g. These figures assume 4000 kcal per kg of dry matter, so the calculator compares protein per 1000 kcal.

FEDIAF recommends at least 25 g of protein per 100 g of dry matter for adult cats, and 33.3 g for less active and neutered cats. Kittens need at least 28 g. The minimum fat for cats is 9 g per 100 g of dry matter.