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Pet age calculator

Convert your dog’s, cat’s, rabbit’s or horse’s age into human years and see which life stage they are in.

Estimated life stage

Rough human-age comparison
39 years
Life stage
Adult

This is only a broad estimate. Breed, body size, lifestyle and health history can all affect how your pet ages.

If your dog is slowing down, losing weight, eating differently or behaving differently, book a check-up rather than assuming it is simply getting older.

How to use it

How the pet age calculator works

Enter your pet’s age and, for a dog, their size. Dogs and cats grow up quickly: their first year is roughly 15 human years and their second about 9 more. After that a cat adds about 4 human years a year, and a dog between 4 and 7 depending on size, because larger breeds age faster. Rabbits and horses use simpler estimates.

Treat the result as a prompt to think about your pet’s care, not as a diagnosis. Two animals born on the same day can age very differently. What matters most is whether you have noticed changes in their weight, movement, appetite, thirst, toilet habits or behaviour.

What the result means

  • For a young animal, ask your vet about growth, vaccinations, parasite prevention, socialisation and neutering.
  • For an adult animal, keep an eye on weight and dental health, stay up to date with parasite prevention, and learn what is normal for them.
  • For a mature or senior animal, watch for changes in weight, movement, teeth, thirst, appetite, toilet habits or behaviour, and consider check-ups every six months.
  • For a horse, age is only part of the picture. Workload, teeth, hoof care, body condition and signs of stiffness also matter.

Changes to discuss with your vet

Contact your vet if your pet slows down suddenly, gains or loses weight without an obvious reason, drinks more, seems stiff, eats differently, develops bad breath, coughs, hides, becomes unsettled or stops enjoying their usual activities. Don’t assume a change is simply part of getting older.

Common questions

Is one pet year the same as seven human years?

No. It is a popular shortcut, but animals don’t age at a fixed rate. Dogs and cats mature quickly in their first two years, then age more slowly, and large dogs age faster than small ones.

Why does dog size change the result?

Larger dogs tend to have shorter lifespans and often reach their senior years earlier than smaller dogs. The calculator uses size to reflect that broad difference.

Does the calculator diagnose health problems?

No. It gives a rough life-stage estimate. It can’t explain symptoms or replace a veterinary examination.

Use the result as a starting point

These tools are planning aids, not a diagnosis or a replacement for veterinary advice. If a pet is unwell, has eaten something risky, or you are unsure what to do next, contact a vet.

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