"Kio estas via aĝo?"

Translation: What is your age?

[nim_numb]

There was a sentence here in one of the lessons:
"kiu estas via numero de telefono?".
I assumed that "kiu" is being used in this case because the speaker assumes that the person he asks knows their telephone number.

If I ask someone for their age, I pre-assume that this person already knows their age.
So, in this case, Is it possible to use "kiu" as well?

[RudolfFischer]

Neither "kiu" nor "kio". "age" is a dimension term, the response indicates a quantity.
Traditional one asks for age by:
Kiom da jaroj vi havas?
Less often: Kiel/Kiom vi aghas?

[noureddin95]

It's a long debate. This page should help, I hope.

[ronstrelecki]

Nice userpic!

[noureddin95]

Thanks! :D

[Bossy99]

Kio estas mia aĝo denove

[ronstrelecki]

I thought it was "traditional" or idiomatic in Esperanto to ask how many years one has. Kiom da jaroj vi havas?

[mensogulo]

All roads lead to Rome. Just use one that you like.

[Bitspark]

Ŝi ĵuris, ke ŝi estis super dek ok...

[-Zorua-]

Haven't we had this question about twenty times now?

[Majklo_Blic]

La Aĝo de Amforo.

[Flink91]

Sounds like “kiu” and not “kio”… The sound quality of the esperanto course is so bad :(

[deactivated user]

Strange. Mi preferas "kiom vi aĝas?".