助詞N3
〜くらい・〜ぐらい
about... / to the extent of...
Structure
数量 + くらい/ぐらい；V-辞書形 + くらい/ぐらい；N + くらい/ぐらい
Explanation
Indicates an approximate quantity or degree, "about... / to the extent of...". Can also give a minimal example (3時間ぐらい, 歩けるくらい).
Examples
家から駅まで15分ぐらいかかります。
It takes about 15 minutes from home to the station.
喉が痛くて、水も飲めないくらいです。
My throat hurts so much I can't even drink water.
Note
くらい/ぐらい marks degree or approximate quantity; ぐらい is more common in speech.
Related Grammar
〜ほど〜ごろ