Cat Calorie Calculator
Enter your cat's weight and life stage, plus the calorie figures from your food labels. You get calories per day from the veterinary RER formula, in grams of dry food and cans of wet.
use ideal weight if your cat is overweight
typical dry cat food: 350-420
a 3 oz can is usually 70-100 kcal
Calories per day
261 kcal
RER 218 × 1.2
As dry food
69 g
about 2.4 oz at 380 kcal/100 g
As wet food
2.9 cans
at 90 kcal each
Daily calories by weight and life stage
RER = 70 × kg^0.75, multiplied by the life-stage factor. Neutering drops a cat's needs by roughly a quarter, which is why so many cats gain weight in the year after -- the food stayed the same.
| Weight | RER | Kitten× 2.5 | Neutered adult× 1.2 | Intact adult× 1.4 | Weight loss× 0.8 | Senior× 1.1 |
|---|---|---|---|---|---|---|
| 6 lb | 148 | 371 | 178 | 208 | 119 | 163 |
| 8 lb | 184 | 460 | 221 | 258 | 147 | 202 |
| 10 lb | 218 | 544 | 261 | 305 | 174 | 239 |
| 12 lb | 249 | 624 | 299 | 349 | 200 | 274 |
| 14 lb | 280 | 700 | 336 | 392 | 224 | 308 |
| 16 lb | 310 | 774 | 371 | 433 | 248 | 340 |
| 18 lb | 338 | 845 | 406 | 473 | 270 | 372 |
| 20 lb | 366 | 915 | 439 | 512 | 293 | 402 |
kcal per day. A healthy adult house cat is usually 8-11 lb; use ideal weight for the weight-loss column.
Turning calories into food
- Dry food: grams = calories ÷ (kcal per 100 g) × 100. A kitchen scale beats a scoop: a "cup" of kibble is 90-130 g depending on the kibble size, which is a 40% swing.
- Wet food: cans = calories ÷ kcal per can. A 3 oz can is 70-100 kcal; a 5.5 oz can 150-190. The label says.
- Mixed feeding: decide the wet portion first (say one can), subtract its calories, and give the remainder as weighed dry.
- Treats: at most 10% of the day, and they come out of the food, not on top of it.
Frequently Asked Questions
How many calories does a 10 lb cat need?
About 261 kcal a day for a neutered adult: RER is 70 × 4.5^0.75 ≈ 218 kcal, times the 1.2 factor. An intact adult needs about 305; an inactive senior about 239. That is roughly a quarter to a third of a cup of dry food, or two and a half 3 oz cans.
Why does my cat seem hungry on this amount?
Cats ask for food out of habit and boredom as much as hunger, and free-feeding dry food has trained many of them to expect it always available. Splitting the daily amount into 3-4 small meals, or using a puzzle feeder, satisfies the behaviour without adding calories. If a cat is genuinely losing weight on the calculated amount, that is a vet visit -- hyperthyroidism and diabetes both present as hunger.
Wet or dry -- does it change the calories?
No, calories are calories, but the density is very different: dry food runs 350-420 kcal per 100 g, wet food 70-110 kcal per 3 oz can. The same 250 kcal is about 65 g of kibble or nearly three cans. Wet food's water content is a real advantage for cats prone to urinary problems.
How fast should an overweight cat lose weight?
Slowly: 0.5-1% of body weight per week, no more. Cats that lose weight too fast -- especially obese cats that stop eating -- can develop hepatic lipidosis, which is life-threatening. Use the 'weight loss' factor on the ideal weight, weigh every two weeks, and never crash-diet a cat.
These calculators use published veterinary formulas and are for general guidance. They are not a diagnosis and do not replace your veterinarian, who knows your animal's breed, history, and body condition.