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Cat food calculator
Work out how many calories your cat needs each day, and how much wet or dry food that is.
Your cat's daily calories and portion sizes will show here.
A starting point, not a prescription. Cats with health conditions need a plan from their vet. Last reviewed October 6, 2026.
How this calculator works
The calculator first works out your cat's resting energy requirement (RER), the calories needed just to keep the body running:
RER = 70 × (body weight in kg)0.75
RER is then multiplied by a factor for life stage and lifestyle. The factors below come from the Pet Nutrition Alliance's veterinary calorie sheet.
| Cat | Daily calories |
|---|---|
| Adult, spayed or neutered | 1.2 × RER |
| Adult, not spayed or neutered | 1.4 × RER |
| Inactive or prone to weight gain | 1.0 × RER |
| Weight loss (use ideal weight) | 0.8–1.0 × RER |
| Growing kitten | 2–3 × RER |
| Pregnant | 2–3 × RER |
Example: a spayed 10 lb (4.5 kg) cat has an RER of about 218 kcal, so it needs about 260 kcal a day. With a wet food at 90 kcal per can, that's just under 3 cans a day.
Mixing wet and dry food
If you feed both, work in calories rather than cans or cups. For example, if your cat needs 260 kcal and gets one 90 kcal can, the dry food should supply the remaining 170 kcal. Enter the dry food's kcal per cup to see how much that is.
Indoor cats easily gain weight. Use the result as a starting point, weigh your cat every few weeks, and adjust if their weight changes in a way you didn't plan. Treats count too: keep them to about 10% of the daily calories.
Questions people ask
How much should I feed my cat a day?
It depends on weight, life stage and the calories in the food. A spayed or neutered adult cat needs about 1.2 times its resting energy requirement. Enter your cat's weight and the kcal per can or cup from the label above to get the amount.
How many calories does a cat need per day?
As a rough guide, a spayed or neutered adult cat of 8 lb needs about 220 kcal, 10 lb about 260 kcal, 12 lb about 300 kcal and 15 lb about 355 kcal a day. Cats that are overweight or very inactive need less.
How much wet food should I feed my cat?
Divide your cat's daily calories by the kcal per can on the label. Cans vary a lot in size and calories, so always check your specific food rather than going by the number of cans.
How much should I feed my cat to lose weight?
Weight-loss plans for cats are usually based on the ideal weight at 0.8 to 1.0 times RER. Cats should lose weight slowly: cutting food too fast can be dangerous for them, so get a plan from your vet.
How much should a kitten eat?
Growing kittens need 2 to 3 times their RER, much more per pound than adults. Feed a kitten food, split into several small meals, and weigh your kitten weekly to check steady growth.