Cat Calorie Calculator
Updated
Quick answer
How many calories should a cat eat?
A typical 10-pound neutered cat needs about 260 kcal a day. The math behind it: resting needs (RER) are 70 × weight in kg^0.75, about 218 kcal for 10 pounds, multiplied by 1.2 for a neutered adult. Kittens need 2 to 3 times as much per pound; weight-loss plans run on less.
| Cat | 8 lb | 10 lb | 15 lb |
|---|---|---|---|
| kcal/day | 221 | 261 | 354 |
How many calories does a cat need?
Two numbers decide it. First, the resting energy requirement:RER = 70 × (weight in kg)^0.75, the calories burned just existing. Second, a life-stage multiplier1: 1.2 for a neutered adult, 1.4 intact, 1.0 for the dedicated napper, 2 to 3 for kittens and pregnancy, up to 6 while nursing a big litter. The calculator shows both numbers so you can check the working.
The honest footnote, straight from the veterinary source: individual cats vary from these estimates by as much as 50%1. Use the number as a starting point and steer by body condition. To turn calories into cans and cups, the cat food portion calculator finishes the job.
Cat calorie chart by weight
| Weight | RER (kcal) | Daily need (kcal) |
|---|---|---|
| 6 lb (2.7 kg) | 148 | 178 |
| 8 lb (3.6 kg) | 184 | 221 |
| 10 lb (4.5 kg) | 218 | 261 |
| 12 lb (5.4 kg) | 249 | 299 |
| 15 lb (6.8 kg) | 295 | 354 |
| 20 lb (9.1 kg) | 366 | 439 |
Calories for weight loss
Weight-loss calories are built on the ideal weight, at about 0.8 to 1.0 × its RER1. Pick "Weight loss" in the calculator and enter the target weight your vet recommends. One feline-specific warning: cats must lose weight slowly. Rapid weight loss can trigger hepatic lipidosis, a serious liver condition, so a cat diet is always a vet-supervised project.
Reading calories on the label
Every complete cat food states its calories as "kcal ME" per can, cup, or kilogram. Typical 5.5-oz cans run 150 to 200 kcal; dry food spans roughly 300 to 500 kcal per cup, which is why "a cup" means nothing without the label. Daily target ÷ label calories = the portion, and the portion calculator does it in one step.
How it works
Even a cat whose main hobby is napping burns energy all day: breathing, digesting, keeping warm, maintaining opinions. Vets estimate that baseline from body weight, then scale it for the life stage: kittens burn double or triple, a spayed indoor adult runs lean. That's the whole method; here are the numbers.
The baseline is RER = 70 × (weight in kg)^0.75, identical for cats and dogs1. The daily number, MER, multiplies it by a life-stage factor: neutered 1.2, intact 1.4, inactive 1.0, weight loss 0.8 to 1.0 of ideal weight, kittens 2 to 3, gestation 2 to 3, lactation 2 to 6. Where the source gives a range, the calculator uses the midpoint and this page shows the range.
The same method powers professional tools like the Pet Nutrition Alliance calculator2 and follows the WSAVA global nutrition guidance3.
Frequently asked questions
How many calories should a cat eat a day?
A typical 10-pound neutered cat needs about 260 kcal a day; an intact adult about 300; a very inactive indoor cat closer to 220. Weight drives the number more than anything, which is why the calculator starts there.
How many kcal per day for a cat losing weight?
About 0.9 × the resting needs of the IDEAL weight, so a cat who should weigh 10 pounds gets about 195 kcal regardless of current weight. Weight loss in cats must be slow; crash-dieting risks liver disease, so run the plan with your vet.
What is RER and what is a cat RER calculator?
RER is the resting energy requirement: 70 × (weight in kg)^0.75, the calories a cat burns at rest. Every vet calorie tool starts from it; the calculator above shows your cat's RER and then multiplies by the life-stage factor.
How many calories are in cat food?
Labels state it as "kcal ME" per can or per cup: a 5.5-oz can commonly runs 150 to 200 kcal, and dry food about 300 to 500 per cup. Divide your daily target by the label value; the food portion calculator does exactly that.
How many calories does a kitten need?
Two to three times an adult of the same weight: about 3 × RER under 4 months, and 2 × RER from 4 to 12 months. Pick the kitten stage in the calculator and re-run it as the weight climbs.
How much water should a cat drink a day?
A common veterinary rule of thumb is roughly 45 to 60 ml per kg of body weight daily, food moisture included; wet food covers most of it, dry food very little. Fresh water always available, and a cat who suddenly drinks much more needs a vet visit.
References
- 1.Pet Nutrition Alliance. Calculating Calories Based on Pet Needs (RER/MER factor table). petnutritionalliance.org
- 2.Pet Nutrition Alliance. Calorie Calculator for Cats and Dogs. petnutritionalliance.org
- 3.WSAVA Global Nutrition Committee. Global Nutrition Guidelines. wsava.org
