How to calculate the daily cost of a kibble?

Cost per day is worked out in two steps: daily ration = the animal's energy requirement divided by the food's density; cost per day = ration multiplied by the price per gram. This method makes two kibbles comparable whatever their density or bag format. In depth ### The formula, step by step Cost per day translates a bag's price into a real daily spend. First estimate the animal's daily energy requirement, say 600 kcal for a medium dog. Then read the food's density, say 375 kcal per 100 g, which gives a ration of 160 g per day. Multiplying that ration by the product's price per gram yields a cost per day directly comparable from one food to another. This energy basis is the one WSAVA recommends, advising reasoning in grams per 1,000 kcal rather than by weight sold (WSAVA, 2021). A useful point: the same calculation, divided then multiplied by 30, gives a reliable monthly cost, whereas a monthly figure estimated without going through the ration stays wrong as soon as densities differ. ### Securing the input data The quality of the result depends on the density used. An energy figure from the modified Atwater method can be underestimated; asking for the tested metabolisable energy reduces that risk (Petfoodindustry). Ration tools from Kibbs or Hector Kitchen help estimate the need, but the chosen product's label stays the reference to verify (Kibbs; Hector Kitchen). Comparison table | Step | Operation | Worked example | |---|---|---| | Daily need | estimate in kcal | 600 kcal | | Density | read on the label | 375 kcal/100 g | | Ration | need / density | 160 g/day | | Cost per day | ration x price per gram | computed by the user |