どれくらいになりますか

how long has it been?

→ どれ
phrase Rare #36,483
how long has it been? A polite way to ask how much time has passed since an event or situation began. It is often used after てから or a verb in the て-form, such as 結婚してどれくらいになりますか (how long have you been married?).
JA: この会社で働き始めて、どれくらいになりますか。
EN: How long have you been working at this company?

あなたとジェイン結婚してどれくらいになりますか

How long have you and Jane been married?

その学校で教えるのをやめてからどれくらいになりますか

How long has it been since you stopped teaching at that school?

あの人から手紙をもらってどれくらいになりますか

How long has it been since you received a letter from that person?