Cat Calorie Calculator
Calculate your cat's exact daily calories using the WSAVA RER formula — by weight, life stage and body condition
🐱 Cat Calorie Calculator
Calculate your cat’s exact daily calorie needs based on weight, life stage and body condition
How Many Calories Does a Cat Need Per Day?
The average neutered adult indoor cat needs around 200–250 calories per day. But this varies significantly based on weight, activity level, reproductive status, and age. Overfeeding by even 10% per day leads to gradual weight gain that compounds into obesity over months.
The RER Formula Explained
This calculator uses the Resting Energy Requirement (RER) formula recommended by WSAVA: RER = 70 x (body weight in kg)^0.75. This is then multiplied by a life stage factor to get the Maintenance Energy Requirement (MER) — the actual calories your cat needs each day.
Why Neutered Cats Need Fewer Calories
Neutering reduces a cat’s metabolic rate by approximately 20–30%. This is why neutered cats are significantly more prone to weight gain than intact cats on the same diet. Most cat owners need to reduce food portions after neutering or switch to a lower-calorie formula.
Wet vs Dry Food
Wet food is roughly 70–80% water, making it much lower in calories per gram than dry kibble. Many vets recommend wet food as the primary diet because cats evolved to get most of their water from food and have a low thirst drive — making dry-only diets a risk factor for urinary tract problems.