How old is Pluto in Pluto years?

You would be 496 years old, because Pluto's orbit around the Sun takes 248 Earth years. (You would also have set a new record for human longevity.)

It is around four billion years old.

455

You would still be 9. Due to the Humans current inability to colonize outside our own planet all calculations, like age, are still based on the Earth standard. But, assuming that was not your...

248 earth years