どのぐらい

駅(えき)まで どのぐらい かかりますか。

Eki made dono gurai kakarimasu ka.

How long does it take to the station?

どのぐらい with かかります is the pairing you hear most

日本語(にほんご)を どのぐらい 勉強(べんきょう)しましたか。

Nihongo o dono gurai benkyou shimashita ka.

How long have you studied Japanese?

どのぐらい asks an amount; いつ asks a point in time

この かばんは どのぐらいですか。

Kono kaban wa dono gurai desu ka.

About how much is this bag?

Softer than いくら for price — it carries an "about"