About

PetCalcHQ is an independent website of free calculators for pet owners. It answers the everyday questions people search for: how old is my dog in human years, how much should I feed my cat, how big will my puppy get, what size crate do I need, and when is she due.

What we do

The site has 29 calculators today. Each page shows the formula or chart it uses and lists its sources so you can check them. Every tool works in pounds and inches or in kilograms and centimetres.

Where our numbers come from

• Published veterinary sources. We use guidelines and references from bodies such as the American Animal Hospital Association (AAHA), the World Small Animal Veterinary Association (WSAVA), the National Research Council (NRC) and the Merck Veterinary Manual, plus peer-reviewed studies. Each page names the source it used.
• Your own labels. Where a result depends on a product, such as calories per cup of food or EPA and DHA per fish oil capsule, you enter the figure from your label.
• Automated tests. Every calculator is tested against published or hand-worked values before it goes live, including checks that it never shows a broken number when a field is empty or zero.
• No medicine dose advice. We never suggest a dose for a medicine. Dosing depends on your pet’s health and other medicines, so it belongs with your vet. Our medication dose calculator only does the arithmetic for a dose your vet has already prescribed (mg per kg into mg, tablets or ml).

What we are not

We are not vets, and nothing on this site replaces a veterinary examination. Our results are general estimates for healthy pets. If your pet is unwell, has eaten something harmful, or needs a change in diet or care, please contact your vet. Read our disclaimer for details.

How the site is funded

PetCalcHQ is free to use. It may show advertising to cover running costs. Ads never change how a calculator works or what it tells you.

Get in touch

Spotted an error, or want a calculator we don't have yet? Send us a message. We read every one, and corrections are our top priority.