How it works
Resting energy is estimated as 70 × weight in kg to the power of 0.75, then multiplied by a life-stage factor — about 1.2 for a neutered adult indoor cat, more for kittens.
Divide by your food's energy (kcal per kg, on the pack) to get grams. Wet food has far fewer calories per gram than dry, so portions look much bigger.
Indoor, neutered cats gain weight easily. Weigh your cat monthly and adjust — and never put a cat on a crash diet; ask your vet before cutting food.
Quick reference
| Weight | Calories a day | Grams of dry food |
|---|---|---|
| 3 kg | ≈ 191 kcal | ≈ 50 g |
| 4 kg | ≈ 238 kcal | ≈ 63 g |
| 5 kg | ≈ 281 kcal | ≈ 74 g |
| 6 kg | ≈ 322 kcal | ≈ 85 g |
Daily energy for a neutered adult cat (factor 1.2), and grams of a 3,800 kcal/kg dry food.
Questions
How much should I feed my cat a day?
A 4 kg neutered adult cat needs roughly 240 kcal a day — about 60 g of a typical dry food. Mixed wet and dry feeding splits that total between them.
Can I free-feed my cat?
Some cats manage it, but many overeat. Measured meals make it easier to keep them at a healthy weight and to notice if appetite changes.
My cat is losing weight but eating well — is that normal?
No. Weight loss despite a good appetite is a reason to see your vet.
General guidance for healthy pets, not veterinary advice. Needs vary — your vet can advise for your pet.