If you want to know someone's age, in English you ask “How old are you?” And in Russian you say...
“How many summers are you?”
Сколько тебе лет?
лето - summer
лет means years but originally it was summers.
We usually don't think of summers when talking about age, but that's what the word really means in Russian.
— Сколько тебе лет?
— Мне 26 лет.
P.S. In Russia it's kinda impolite to ask a woman about her age ;-). Especially if she is not young.