Cat food calculator
The amount is calculated with the RER formula and the multipliers used in veterinary practice: weight, age, neutering and activity level. Cats need less than dogs of the same weight, so the multipliers differ.
How much food your cat needs
CalculationGrowing and senior animals are calculated differently.
5 is ideal. Ribs can be felt but not seen, and the waist is visible from above.
Kibble. Usually around 3600 kcal per kilogram — the exact figure is on the bag.
Dry food is usually 3,300–4,500 kcal per kg. If the bag gives it per 100 g, multiply by 10: 380 kcal per 100 g is 3,800.
No date of birth on file — calculated as an adult animal.
No more than a tenth of the daily allowance. A treat is balanced for pleasure, not for need, and a larger share skews the diet even when the calories add up. This is where weight is usually gained: the food is weighed, the biscuits are not.
What it costs
Switching to another food?
An abrupt switch is the most common cause of diarrhoea in a healthy animal. The new food usually gets the blame, though the speed is at fault. The daily total stays the same — only the proportions change.
| Day | Old food | New food |
|---|---|---|
| 1 | 75% | 25% |
| 2 | 62% | 38% |
| 3 | 50% | 50% |
| 4 | 37% | 63% |
| 5 | 25% | 75% |
| 6 | 12% | 88% |
| 7 | 0% | 100% |
This is an estimate, not a prescription. Discuss your pet's diet with a veterinarian.
Create a profile so the amount recalculates itself at every weigh-in and vaccinations remind you themselves. Create a profile