How long is 1 guinea pig year?

There's no such thing as a "guinea pig year" in the same way that we have human years.

However, guinea pigs age much faster than humans. Here's how we generally think about their lifespans:

* 1 Guinea pig year = ~6 human years

This means that a guinea pig that's 5 years old is considered to be about 30 years old in human years.