Cat Ideal Weight Calculator
Wondering if your cat is overweight? Enter their weight and a quick hands-on body-condition check to estimate a healthy target.
Ribs felt with slight pressure; waist starting to disappear.
A body-condition estimate, not a breed standard. In cats even a pound or two of excess is a lot — your vet can confirm the target and a safe plan to reach it.
Estimate only — not veterinary advice. Every animal is different; for a medication dose, a possible poisoning, or any emergency, call your veterinarian or an animal poison control line right away.
How this calculator estimates an ideal weight
Rather than guess from breed, this tool uses body condition score— the same hands-on system vets use. Each point above the ideal 5/9 represents roughly 10% over a healthy weight, so it divides your cat's current weight by that factor to estimate the target. It's an estimate to show you the gap, not a substitute for your vet weighing in.
Getting to a healthy weight
The safe path is measured meals and time. Switch from free-feeding to weighed portions, use the cat calorie calculator to set the daily target, and check with your vet before starting — especially for a very overweight cat, where weight must come off slowly to protect the liver. Small, consistent changes beat any crash diet.
Frequently asked questions
- How do I know if my cat is overweight?
- Feel and look, don't just weigh. With a hand flat on your cat's side you should be able to feel the ribs under a thin layer of fat (like the back of your hand), see a slight waist from above, and see the belly tuck up behind the ribcage from the side. If the ribs are hard to find and there's no waist, your cat is likely overweight. The soft flap of skin low on the belly — the 'primordial pouch' — is normal and isn't fat.
- How much should my cat weigh?
- It depends on frame, not a single number, but many domestic cats land around 8–11 lb (3.6–5 kg). This calculator works backward from your cat's current weight and body condition to estimate a healthy target rather than guessing from breed. For most cats a body condition score of 5/9 is ideal.
- Why is even a little extra weight a big deal for cats?
- Cats are small, so a pound or two is a large share of their body — a 15 lb cat that should be 10 lb is 50% overweight, like a 200 lb person being 100 lb over. Excess weight raises the risk of diabetes, arthritis and urinary problems, and shortens life. The upside: small, steady changes make a real difference.
- How fast can a cat safely lose weight?
- Slowly. Crash diets are dangerous in cats and can trigger fatty liver disease (hepatic lipidosis). Aim for about 0.5–2% of body weight per week under a vet's guidance, usually with measured meals of a portion-controlled food. Never starve a cat to slim them down.
Sources
These are the references behind this calculator. Where a source gives a range we take the midpoint and round toward caution, and where we go beyond what a source states — an extra safety margin, or a rule of thumb rather than a clinical threshold — the page says so in the text above.
- Obesity in cats — VCA Animal Hospitals
- Global Nutrition Guidelines — WSAVA