Looking on the internet deeply has found these results:

how old are you is the most popular phrase on the web.

what is your age 163,400 results on the web	how old are you 11,770,000 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
Apr 15, 2015 ... For instance, I would consider it more polite for the receptionist at a doctor's office to ask "What is your age?" rather than "How old are you? 1 day ago ... Do you call people "noobs" and what is your age? Add a reply. Alr3m1 #1896. View posts. Alr3m1. Posts: 1,580. I'm just curious of the ... Apr 26, 2015 ... I'm quite sure that both are correct. I'm not really sure that What is your age? is really more formal, though a lot of people feel so. And I have ... 4 days ago ... Not: What is your age? How old is your car? Not: What age is your car? We only use What age …? in more formal situations: What age was the ...	Mrs. Gallagher, how old are you? Excuse me, but how old are you? Mr Little, how old are you? Okay, how old are you? One question: how old are you? Wait, how old are you guys? 22. And how old are you, Charlotte? Miss Coulson, how old are you?

what is your age

163,400 results on the web

how old are you

11,770,000 results on the web

More popular!

Apr 15, 2015 ... For instance, I would consider it more polite for the receptionist at a doctor's office to ask "What is your age?" rather than "How old are you?
1 day ago ... Do you call people "noobs" and what is your age? Add a reply. Alr3m1 #1896. View posts. Alr3m1. Posts: 1,580. I'm just curious of the ...
Apr 26, 2015 ... I'm quite sure that both are correct. I'm not really sure that What is your age? is really more formal, though a lot of people feel so. And I have ...
4 days ago ... Not: What is your age? How old is your car? Not: What age is your car? We only use What age …? in more formal situations: What age was the ...