How old is my rabbit, ferret or rat in human years?

There is no published epigenetic clock for most companion small mammals, so these figures come from a transparent model anchored on two points: age at sexual maturity mapped to human 22, and median lifespan in good captive care mapped to human 78. Lifespan data is drawn from AnAge and the exotic companion mammal veterinary literature.

That is an estimate, and we would rather say so than present it with the same confidence as the dog and cat figures, which come from peer-reviewed research.

Small pet years to human years

Age	Rabbit	Ferret	Guinea Pig	Rat	Chinchilla	Hedgehog
6 mo	22	22	34	46	12	22
1 yr	35	37	46	60	29	39
2 yr	48	51	59	74	42	56
3 yr	55	60	66	82	49	66
4 yr	61	66	71	87	55	73
5 yr	65	71	75	—	59	78
6 yr	68	75	78	—	62	82
8 yr	74	81	83	—	68	89
10 yr	78	86	87	—	72	95
12 yr	81	—	90	—	75	—
14 yr	84	—	—	—	78	—

A dash means the age exceeds the documented maximum for that species. Figures assume good captive care — indoor housing, appropriate diet, and veterinary attention.

Typical lifespans

Species	Typical lifespan	Documented maximum	Human years gained per year
Rabbit	10 years	14 years	2
Ferret	7 years	11.1 years	3
Guinea Pig	6 years	12 years	3
Rat	2.5 years	4.7 years	10
Chinchilla	14 years	20 years	1
Hedgehog	5 years	10 years	5

The final column is measured near the end of life, where ageing has slowed. Early in life the rate is far higher — a rat's first year alone covers well over half a human lifetime.

What shortens these lives

Rabbits live far longer indoors and neutered. Uterine cancer is common in unspayed females, and outdoor hutch rabbits face predator stress, temperature extremes and undetected illness.

Ferrets in the United States tend toward the short end of their range, largely because of adrenal disease associated with very early neutering — a practice more common in the US than in Europe, where ferrets often live longer.

Guinea pigs cannot synthesise vitamin C and require it in their diet. Deficiency is a common and entirely preventable cause of early death.

Rats are prone to mammary tumours and respiratory disease. Their lives are short enough that a single untreated illness accounts for a large fraction of the total.

Common questions

How old is a 2 year old rat in human years?

About 70. Rats have a median lifespan of roughly two and a half years, so a two-year-old rat is genuinely elderly and likely to show visible age-related changes.

How long do rabbits live?

Indoor, neutered rabbits commonly reach 8 to 12 years, with a documented maximum around 14. Outdoor hutch rabbits average considerably less.

Why do ferrets in the US live shorter lives?

Adrenal disease is common in American pet ferrets and is associated with neutering at a very young age, which is standard practice for ferrets sold through US pet retailers.

Which small pet lives longest?

Chinchillas, comfortably. They commonly reach 14 years and have been documented to 20 — remarkable for a rodent of that size, and a serious commitment to take on.

Are these numbers as reliable as the dog and cat figures?

No, and we label them as estimates. Dogs use a peer-reviewed epigenetic clock and cats use veterinary guidelines. For small pets no equivalent research exists, so we use a transparent model based on published maturity and lifespan data.

Other species