Cat Food Calculator: How Much Wet and Dry Food a Day
By the Pets Locally team
Updated 2026
Most cats are fed a mix of pouches and biscuits, and the feeding guide on each pack assumes that food is the only thing in the bowl. Feed both at full pack amounts and your cat gets close to double its needs. This calculator works out your cat's daily calories from its weight and life stage, then splits them between wet and dry food using the energy figures printed on your packs.
How much should I feed my cat?
For an overweight cat, use the target weight your vet gives you.
Sets the multiplier applied to resting energy.
Slide to 0 for biscuits only or 100 for pouches only.
The daily amount is split evenly across meals.
Printed as "energy" or "metabolisable energy" on the bag. Example value: replace it with yours.
From the pouch, tray or tin label. Example value: replace it with yours.
Used to convert grams of wet food into pouches.
Treat calories are taken off the meal amounts.
How the cat food calculator works
Vets estimate a cat's resting energy requirement (RER) as 70 multiplied by its bodyweight in kilograms raised to the power 0.75. That is the energy a cat burns lying still in a comfortable room. Multiplying RER by a life-stage factor gives the daily calorie target: about 1.2 for a typical neutered adult, 1.4 for an entire adult, 1.0 for an indoor or lazy cat, 0.8 for weight loss and 2.5 for a growing kitten. The calculator then divides those calories between wet and dry food in the proportion you choose and converts each share to grams using the energy figure on the label.
If your pack only gives kilojoules, pick kJ/100g and the tool converts it (1 kcal is 4.184 kJ). If the label lists energy per pouch rather than per 100g, divide by the pouch weight and multiply by 100 first.
Getting the portion right
- Weigh dry food. A cup or scoop can vary a lot depending on kibble size and how full it is. A kitchen scale takes the guesswork out.
- Check weight every few weeks. These formulas are averages and individual cats differ. If your cat is gaining, cut the daily amount by around 10% and re-check; if it is losing weight without trying, increase it and speak to your vet.
- Change food gradually. Mix the new food in over about a week to avoid upset stomachs.
- Ask a vet first for kittens with health problems, pregnant or nursing queens, and cats with kidney disease, diabetes or thyroid problems, as their needs differ from these estimates.
Going away? Our guides to cat boarding costs and finding a cat sitter help you pass the right feeding instructions on, and the cat age calculator tells you when your cat counts as a senior.
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