How old do wolves generally live?

Usually 15 to like 18ish

A wolf's life, on average, is around half of a real-life year.

This^

But I'd like to add that Raven feathers (available during the Halloween event) can be used on a wolf to decrease their chnace of dying. Your wolf has a chance to live 20-26 years when using raven feathers. Without the feather, most wolves die around 16-18 years old. With the feather being used every year (after 15 y/o), you're more likely to see them live to be 20+

The highest age a wolf can live (without the use of an Apple item) is actually 26 I believe, if they're born at the right time.

Thanks for all the help!