About Pet Calculator

Pet Calculator is a free set of health and safety calculators for dog and cat owners. Check whether something your pet ate is toxic, convert their age to human years, estimate a healthy weight, work out medication doses by weight, plan a due date, and more. Everything runs instantly in your browser, with no account and nothing to install.

How the numbers are worked out

Each calculator uses a published, widely-used veterinary method, and we explain it in plain language on every page: the theobromine dose behind chocolate toxicity, the resting-energy formula behind calorie needs, the modern size-adjusted method behind dog years, and so on. Where a result depends on a judgement call, such as body condition, we say so.

Not a substitute for your vet

These tools give fast estimates to help you decide what to do next. They are not a diagnosis and they do not replace professional veterinary advice. In an emergency — a suspected poisoning, trouble breathing, or a collapse — call your veterinarian or an animal poison control line right away.

Privacy

Whatever you type about your pet stays on your device. The calculators are pure client-side JavaScript and we don't store your inputs. See our privacy page for details.