How is a cat's daily food portion calculated?

The calculator estimates daily calories from body weight and life stage, then divides that target by the selected food's energy density. The result is a starting portion that should be adjusted according to weight and body condition.

Should cat food be measured in grams or cups?

Grams are more accurate because small measuring differences can be significant for cats. A kitchen scale is preferable, especially for dry food and weight-management plans.

Can this calculator be used for both wet and dry cat food?

The calculation works when the food has a reliable energy value, but this public preview currently focuses on selected foods in the verified catalogue. For mixed feeding, calculate each food's calorie contribution so the combined daily total stays within the target.

How often should a cat's portion be reviewed?

Check weight and body condition regularly and review the portion after a food change, neutering, a change in activity or any noticeable weight change. Kittens, pregnant or nursing cats and cats with medical conditions need veterinary guidance.

Free preview — featured foods

Cat Food Portion Calculator

Cats are small, so portion errors matter more. Pick a food, get grams per day for that exact product, and print a handout the owner can stick on the fridge. This page previews one featured food per life stage — the full verified catalog opens with a free account. Need calories only? The cat calorie calculator is completely open, no sign-up.

Work out the daily portion

Pick the food your client actually feeds and get grams per day, using the energy figures on file for that product, not a generic average.

Country

Body weight

Life stage / status

Meals per day

Select the food

A featured selection, by life stage

This page shows one verified cat food per life stage. Start your 7-day free trial to unlock the complete verified catalogue and prescription diets.

Start free trial

Or enter food energy from the bag (kcal per kg)

Daily energy (MER)

260 kcal / day

Resting (RER) 216 kcal / day

Daily portion

Select a food or enter kcal per kg to see grams.

In cups

No kcal per cup on file for this food, so we stay in grams. Weighing is always more accurate.

Estimates for healthy adult cats. Growing, pregnant, lactating or therapeutic-diet patients need a veterinary feeding plan.

How a cat food portion is calculated

The calorie target starts with resting energy requirement, then a life-stage factor, then the food’s own energy density:

RER = 70 × (weight in kg)^0.75

grams per day = (RER × factor) ÷ kcal per gram

Cats use lower factors than dogs

A neutered indoor cat sits around 1.2 × RER, versus 1.6 for a comparable dog. Cats also carry far less margin for error: a 4 kg cat overfed by 30 g of dry food a day is eating roughly 25 percent more than it needs, which is why so many indoor cats drift into overweight body condition without anyone noticing.

Cups are the usual culprit

Most owners feed “a cup” from a mug or scoop that has never been measured. This tool shows a cup figure only when the product has a kcal-per-cup value on file, and always leads with grams. For cats, a scale is not a nicety — it is the difference between a weight-loss plan working and stalling.

Built for veterinary clinics

The full Vet.Portions dashboard adds branded handouts, prescription diet support, food transition schedules and parasite dosing across your whole product range.

Create a free account Dog food portion calculator Cat calorie calculator Dog calorie calculator Read the full calorie guide

Frequently asked questions

How is a cat's daily food portion calculated?: The calculator estimates daily calories from body weight and life stage, then divides that target by the selected food's energy density. The result is a starting portion that should be adjusted according to weight and body condition.
Should cat food be measured in grams or cups?: Grams are more accurate because small measuring differences can be significant for cats. A kitchen scale is preferable, especially for dry food and weight-management plans.
Can this calculator be used for both wet and dry cat food?: The calculation works when the food has a reliable energy value, but this public preview currently focuses on selected foods in the verified catalogue. For mixed feeding, calculate each food's calorie contribution so the combined daily total stays within the target.
How often should a cat's portion be reviewed?: Check weight and body condition regularly and review the portion after a food change, neutering, a change in activity or any noticeable weight change. Kittens, pregnant or nursing cats and cats with medical conditions need veterinary guidance.