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Cat Food Calculator

Enter your cat's weight and life stage, then the calories in your foods. Choose how much of the diet is wet food and the calculator splits the day into cans and cups.

Your cat

lb

Your foods

%
kcal
kcal

A 3 oz can usually has 70-100 kcal and a 5.5 oz can 150-200 kcal. The exact number is on the label.

Calories per day
0kcal
Wet food
-
Dry food
-
Dry food in grams (approx.)
-
Resting energy (RER)
0
A starting point. Weigh your cat monthly and adjust by about 10%. Never let a cat go without food for more than a day: it can cause fatty liver disease.

Estimates for planning only, not veterinary advice. Check with your vet before you change food or give medicine. Terms

Question about this calculator? Ask us.

How much should I feed my cat?

Most indoor adult cats need only about 200 to 280 calories a day. Vets work it out from the resting energy requirement (RER), then multiply by a factor for life stage. Because many indoor cats are not very active, the factors are lower than for dogs.

RER = 70 × (weight in kg)^0.75
Daily calories = RER × life stage factor
Cans = wet share × calories ÷ kcal per can

Life stage factors for cats

CatFactor × RER
Kitten up to 1 year2.5
Adult, spayed or neutered1.2
Adult, intact1.4
Inactive or prone to weight gain1.0
Weight loss0.8 × RER at the target weight
Senior, normal weight1.1 (older cats over 12 may need more)

Worked example

A 10 lb (4.5 kg) neutered adult: RER = 70 × 4.54^0.75 = about 218 kcal. Daily calories = 218 × 1.2 = 261 kcal. Half from wet food is 131 kcal, about 1.5 cans of an 85 kcal can. The other half from dry food at 400 kcal per cup is about ⅓ cup.

Daily calories by weight (neutered adult)

WeightDaily calories
6 lb178 kcal
8 lb221 kcal
10 lb261 kcal
12 lb299 kcal
15 lb354 kcal

Wet or dry food?

Both can be complete diets. Wet food adds water, which helps cats that drink little and those with urinary or kidney problems, and it is easier to portion for weight loss. Dry food is cheaper and can be used in puzzle feeders. Many vets suggest a mix. Whatever you choose, measure it: free-feeding dry food is a common reason indoor cats become overweight.

See your cat's age in human years with the cat age calculator. Feeding a dog too? Use the dog food calculator.

Sources: RER formula and feline energy factors as used in WSAVA and Pet Nutrition Alliance guidance and veterinary nutrition texts. Individual needs vary.

Frequently asked questions

How much should I feed my cat a day?

A typical 10 lb neutered indoor cat needs about 260 calories a day. That is about 3 cans of an 85 kcal 3 oz wet food, or about ⅔ cup of a 400 kcal per cup dry food, or a mix of both.

How many cans of wet food should a cat eat?

Divide your cat's daily calories by the calories per can. An average adult cat eats two to three 3 oz cans a day if it gets only wet food.

How much dry food should a cat eat?

Usually about ½ to ¾ cup a day for an adult cat on dry food only, depending on weight and the calories per cup.

How many calories does a kitten need?

About 2.5 times its resting energy requirement until it is a year old. Kittens should be fed several small meals a day.

How can I help my cat lose weight?

Feed about 80% of the resting energy requirement for the target weight, measure every meal, and aim to lose no more than 1% to 2% of body weight a week. Check with your vet first.

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Last updated October 2026.