Feeding a cat the right amount
Overweight cats are common, and most of them simply eat a little more than they need every day. Because cats are small, a few extra kibbles matter. This calculator estimates your cat’s daily calories and splits them between wet food and dry food, which many owners combine.
The formulas
- Resting energy requirement (RER) = 70 × (weight in kg)^0.75 kcal a day
- Daily need = RER × factor: 1.2 for a neutered adult, 1.4 for an intact adult, 1.0 for an inactive or easily overweight cat, 0.8 for weight loss (applied to the target weight), 1.1 for seniors and about 2.5 for kittens
- Wet food = daily need × wet share ÷ calories per can
- Dry food = daily need × dry share ÷ calories per cup
Worked example: a 10-lb neutered indoor cat
- Weight in kg: 10 × 0.4536 = 4.54 kg.
- RER: 70 × 4.54^0.75 = 218 kcal.
- Daily need: 218 × 1.2 = 261 kcal.
- Treats at 10%: 26 kcal, leaving 235 kcal for meals.
- Half from wet food at 180 kcal per 5.5-oz can: 117 ÷ 180 = 0.65 can, about two thirds.
- Half from dry food at 450 kcal per cup: 117 ÷ 450 = 0.26 cup, a generous quarter cup.
Daily calories by weight (neutered adult)
| Weight | Daily need |
|---|---|
| 6 lb | 178 kcal |
| 8 lb | 221 kcal |
| 10 lb | 261 kcal |
| 12 lb | 299 kcal |
| 15 lb | 354 kcal |
Reading the labels
Calorie content is printed on the can or bag, usually as kcal per can and kcal per cup or per kilogram. Values vary widely: dry foods from about 300 to over 500 kcal per cup, wet foods from 60 to 100 kcal per 3-oz can. Always use the numbers of your own food.
Wet, dry or both
Wet food adds water to the diet, which helps cats that drink little and those prone to urinary problems, and it has fewer calories per bite. Dry food is convenient and can be used in puzzle feeders. Mixing both is fine as long as the total calories stay on target.
Watch the cat, not only the numbers
- Weigh your cat once a month. A gain of 0.5 lb on a 10-lb cat is already 5% of its weight.
- You should feel the ribs easily, and see a waist from above.
- Never put a cat on a crash diet. Cats that stop eating can develop a serious liver condition, hepatic lipidosis, within days. Weight loss should be gradual, around 1% of body weight a week, with your vet’s guidance.
- Kittens need more food per pound than adults; recalculate as they grow.