Cat Food Calculator
Calculate daily calories and food portions for your cat by weight, age and lifestyle.
How the Cat Food Calculator Works
The calculator uses the veterinary Resting Energy Requirement formula — RER = 70 × (weight in kg)^0.75 — as the starting point. This baseline is multiplied by a life stage factor that accounts for age, reproductive status and activity level. Kittens need 2.5× their RER to fuel rapid growth. Neutered indoor adults are multiplied by 1.2 — the lowest adult factor — because spaying or neutering reduces metabolic rate by roughly 25%. Intact or outdoor adults get 1.4–1.6×. Seniors drop to 1.1× as they are less active and prone to weight gain. The daily calorie result is then divided by the caloric density of your food: cups for dry kibble (typically 350–420 kcal/cup) and ounces for wet food (roughly 25 kcal/oz). For a mixed diet, the calculator splits daily calories evenly between dry and wet portions.