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Pet Age Calculator

Choose your pet, enter their birth date, and get their age in human-year terms — with a plain-language explanation of what that life stage actually means.

1. Choose your pet

🐶Dog

🐱Cat

🐰Rabbit

🐹Guinea Pig

🐹Hamster

🦜Bird

🐴Horse

2. Size / breed group

Small (up to 20 lb)

Medium (21–50 lb)

Large (51–90 lb)

Giant (91+ lb)

2. Bird type

Small — budgie, canary, finch

Medium — cockatiel, conure, lovebird

Large — macaw, cockatoo, African grey

3. Birth date

Date of birth (or adoption estimate)

Please enter a valid birth date that isn't in the future.

Human-year equivalent

human years

Life stage

Birth 0% of average lifespan —

0y 0m

Actual age

—

Typical lifespan

Of lifespan lived

What this life stage means

How pet age conversion actually works

Pets don't age at a constant multiple of human years — the old "1 dog year = 7 human years" rule doesn't hold up. Most species mature rapidly in their first one to two years, then settle into a slower, steadier aging rate afterward. Dogs, cats, and horses have reasonably well-documented veterinary conversion charts because their aging curves have been studied closely; smaller, shorter-lived pets like hamsters and guinea pigs are far less standardized, so this tool uses a percentage-of-average-lifespan approach for those instead of a fabricated precise number.

Dog age	Small	Medium	Large	Giant
1 year	15	15	15	15
2 years	24	24	24	24
5 years	36	39	42	45
10 years	56	64	72	80

Dog age

Small

Medium

Large

Giant

1 year

2 years

5 years

10 years

Age	Cat (human years)	Horse (human years)
1 year	15	6.5
5 years	36	22.5
10 years	56	35
20 years	96	60

Age

Cat (human years)

Horse (human years)

1 year

6.5

5 years

22.5

10 years

20 years

Frequently asked questions

Is the "1 year = 7 human years" rule accurate for dogs?

No — it's a popularized oversimplification. Dogs age very quickly in year one (roughly equivalent to 15 human years) and year two (up to 24), then age more slowly and steadily afterward, at a rate that depends on their adult size.

Why does dog size affect the conversion?

Larger dog breeds tend to have shorter overall lifespans and age faster in their later years than small breeds, even though both age at a similar rapid pace as puppies.

Why don't rabbits, guinea pigs, and hamsters get a precise human-year number?

Unlike dogs, cats, and horses, there isn't a widely validated veterinary conversion chart for these species. Rather than presenting an invented number as fact, this tool shows how far through their typical lifespan they are instead.

Does this replace a vet checkup?

No. This is a general reference based on typical averages — individual pets vary by breed, genetics, and health history. A veterinarian is the right source for anything specific to your pet.