🐟 Cat Food Calculator
Enter your cat's weight and life stage, plus the calories in the food you use (on the label), to get a daily portion.
How the Cat Food Calculator works
Resting energy requirement (RER) = 70 × weight in kg^0.75, multiplied by a life-stage factor (1.2 for a neutered adult). Divide by the calories per cup or can.
Step-by-step calculation
- 1Enter weight and life stage.
- 2Calculate RER and multiply by the factor.
- 3Divide by food calories.
Worked example
A 4.5 kg (10 lb) neutered adult cat: RER ≈ 216 kcal; × 1.2 ≈ 260 kcal a day — about ⅔ cup of a 400 kcal/cup dry food.
Cat Food Calculator examples
| Cat's weight | Daily food |
|---|---|
| 2.25 | 154 kcal / day |
| 3.38 | 209 kcal / day |
| 4.5 | 260 kcal / day |
| 5.63 | 307 kcal / day |
| 6.75 | 352 kcal / day |
Other inputs kept at the calculator's default values. Results calculated by this calculator.
Why use a Cat Food Calculator?
Prevent over- or under-feeding your cat.
Important factors that can affect your results
- Wet vs dry food calories.
- Neutered cats need less.
- Treats.
Frequently asked questions
Wet or dry food?
Both can be complete diets. Wet food has far fewer calories per gram because of its water.
My cat is overweight. What now?
Ask your vet for a target weight and a safe weight-loss plan; cats should lose weight slowly.
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Last reviewed November 2026 · How we build and check our tools · Report a problem