Cat Calorie Calculator
How many calories does your cat need a day? This free cat calorie calculator works out daily calories (kcal) by weight, age and activity using the vet RER/MER formula — with a weight-loss target, a kitten mode, and wet and dry food portion sizes.
How the Cat Calorie Calculator Works
The five tools cover daily calories, a weight-loss target, kitten growth needs, wet and dry food portions, and the raw RER/MER figures.
Cat Calorie Chart (by Weight)
This chart shows typical daily calories for a neutered indoor adult cat at each weight, using the RER × 1.2 formula. Intact or active cats need more; inactive cats need less.
| Body weight | RER (resting) | Neutered indoor (×1.2) | Intact / active (×1.4) |
|---|---|---|---|
| 5 lb (2.3 kg) | ~130 kcal | ~155 kcal | ~180 kcal |
| 8 lb (3.6 kg) | ~185 kcal | ~220 kcal | ~260 kcal |
| 10 lb (4.5 kg) | ~215 kcal | ~260 kcal | ~300 kcal |
| 12 lb (5.4 kg) | ~245 kcal | ~295 kcal | ~345 kcal |
| 15 lb (6.8 kg) | ~290 kcal | ~350 kcal | ~410 kcal |
| 18 lb (8.2 kg) | ~335 kcal | ~400 kcal | ~470 kcal |
How Many Calories Should I Feed My Indoor Cat?
A typical neutered, indoor adult cat at a healthy 10 lb (4.5 kg) needs about 200 to 250 calories a day. Indoor cats burn less than outdoor ones, so they sit at the lower end — roughly 1.0 to 1.2 times their RER. The quick rule of thumb is about 20 calories per pound of ideal body weight for a lazy indoor cat and around 30 per pound for an active one. Because so many indoor cats are overweight, it is safer to feed to the weight you want rather than the weight they are, and to split the daily amount into measured meals instead of leaving a full bowl out.
Is 200 Calories a Day Enough — or 300 Too Much?
200 calories a day is about right for a healthy 10 lb indoor cat, and it is a sensible maintenance figure for many average adult cats. Whether 300 calories is too much depends entirely on the cat: 300 kcal suits a large (around 14–15 lb healthy weight), active, or intact cat, but it would gradually make a small 8–9 lb indoor cat overweight. There is no single right number — the real test is your cat’s body condition and weight trend over a few weeks. If the ribs are getting harder to feel and the scale is climbing, cut back; if ribs and spine are becoming sharp, feed more.
Wet vs Dry Food: Working Out Portions
Calories, not cups, are what matter — and wet and dry foods differ hugely. Dry food is energy-dense, usually 300–500 kcal per cup, so a small scoop goes a long way. Wet food is mostly water, around 70–120 kcal per 3 oz can, so it takes more volume to hit the same calories but helps with hydration and fullness. Many owners feed a mix. Whatever you choose, read the label for the exact kcal per cup or can, use the Food Portions tab to convert your calorie target into amounts, and weigh dry food in grams on a kitchen scale — measuring cups routinely over-pour and are a leading cause of feline obesity.
How to Help a Cat Lose Weight Safely
Feed to the target weight: take the RER for the weight you want and feed about 80% of it. Aim to lose only 0.5 to 1% of body weight per week — crash diets are dangerous for cats and can trigger hepatic lipidosis (fatty liver), a life-threatening condition. As one r/dechonkers owner put it, their cat needed about 175 kcal a day to drop from 15.8 to 13.5 lb over six to eight months, which is exactly the slow-and-steady pace vets recommend. Weigh your cat every one to two weeks on a baby scale, keep treats under 10% of calories, and have your vet confirm the plan and rule out medical causes.
Frequently Asked Questions
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