階

Counter for Floors

Level 1Sounds Like kai

Use 階 (かい) to count or name the floors of a building. In Japan, the ground floor is always 1階 (いっかい).

How It Works

The counter 階（かい） is essential for navigating Japanese buildings. Unlike some European systems, Japan follows the system where the ground level is the first floor (1階).

Pronunciation Guide:
Here is the complete list from 1 to 10. Pay close attention to the numbers that involve sound changes like gemination or rendaku, or require specific base readings:

  • 1階: いっかい
  • 2階: にかい
  • 3階: さんがい - Note the 'g' sound! (Though さんかい is increasingly common in modern daily life, such as in elevator announcements.)
  • 4階: よんかい - (Note: しかい is not used, as し sounds like 死/death)
  • 5階: ごかい
  • 6階: ろっかい
  • 7階: ななかい or しちかい - (Note: ななかい is overwhelmingly preferred in spoken Japanese because しちかい sounds too similar to 1階/いっかい or 8階/はちかい, especially over the phone or in noisy environments.)
  • 8階: はっかい or はちかい
  • 9階: きゅうかい - (Note: くかい is not used, as く sounds like 苦/suffering)
  • 10階: じゅっかい or じっかい
  • 何階 (which floor?): なんがい - (Like 3階, なんかい is also very commonly heard today.)

Important Distinction: Be careful to distinguish between 3階 (third floor), which traditionally undergoes rendaku to become さんがい, and 3回 (three times) using the counter 回, which remains さんかい.

Note that these irregular pronunciations repeat for higher numbers ending in the same digits (e.g., 11階 is じゅういっかい, 13階 is じゅうさんがい). Multiples of 10 follow the pattern of 10階, so 20階 is にじゅっかい or にじっかい (not にじゅうかい). Also, 100階 is pronounced ひゃっかい.

Indicating Location:
To ask what floor something is on, use the pattern 「[Location] は何階ですか？」 (What floor is the [Location] on?). When stating that something exists on a specific floor, use the location particle に along with verbs of existence like あります (for inanimate objects) or います (for people/animals). For example: トイレは2階にあります（といれはにかいにあります - The restroom is on the second floor).

Basements and Roofs:
To refer to basement levels, add 地下（ちか） before the number. For example, B1 is 地下1階（ちかいっかい）. In everyday casual speech, people frequently use the English-derived ビーワン (B1) or ビーツー (B2). The roof is called 屋上（おくじょう）.

Describing Building Height:
While 階 identifies a floor, adding 建て（だて） describes the total height. For example, a 'five-story building' is 5階建て（ごかいだて）. To ask "how many stories/floors tall?", use 何階建て（なんがいだて or なんかいだて）.

Important Contrast: Be careful not to confuse stating a location with describing a building's total floors. If you want to say "My apartment is on the second floor," use 2階にあります（にかいにあります）. If you want to say "It is a two-story apartment," use 2階建てのアパートです（にかいだてのあぱーとです）.

Examples (5)

  1. すみません、トイレは何階ですか？

    Excuse me, what floor is the restroom on?

    Word by Word: Excuse me, restroom (topic) what floor is it?

    Uses 何 (what) with 階 to ask for a specific floor. Note that 「なんがい」 is the standard pronunciation here.

  2. 私の部屋は三階にあります。

    My room is on the third floor.

    Word by Word: My room (topic) 3rd floor at exists.

    Uses the に particle to indicate the location of the room. Remember that 三階 is pronounced 「さんがい」.

  3. このビルは地下二階まであります。

    This building goes down to the second basement floor.

    Word by Word: This building (topic) basement 2nd floor until exists.

    Uses 地下（ちか） to indicate floors below ground level and まで to mean 'until' or 'as far as'.

  4. 一階で靴を買いました。

    I bought shoes on the first floor.

    Word by Word: 1st floor at shoes (object) bought.

    Uses で to indicate the location where the action (buying) took place. 一階 is pronounced 「いっかい」.

  5. ここは五階建ての図書館です。

    This is a five-story library.

    Word by Word: Here (topic) 5-floor-built 's library is.

    Uses 階建て（かいだて） to describe the total scale of the building rather than just a specific floor.

Common Mistakes

  • Confusing the pronunciation of 'third floor' (3階) with 'three times' (3回).

    三階（さんかい）に行ってください。
    三階（さんがい）に行ってください。

    Traditionally, 3階 undergoes rendaku and is pronounced さんがい, whereas 3回 (three times) using the counter 回 is pronounced さんかい. While さんかい for 3階 is becoming incredibly common in modern everyday Japanese (like in elevator announcements), learning the standard さんがい helps you distinguish it clearly from 'three times'.

  • Calling the ground floor '0階' or the floor above ground '1階'.

    地上階（ちじょうかい）
    一階（いっかい）

    In Japan, the floor at street level is always the 1st floor (一階). If you are from a country where the 1st floor is above the ground floor, you must adjust your count up by one.

How It Connects

Tap a pattern to see what it builds on and what it leads to.

階Level 1Counter for Floors

Learn This First

To understand the counter '階', learners should first be familiar with the general concept of Japanese counters and basic kanji. Knowledge of basic interrogatives like 'doko' is also helpful for practical usage in asking for directions within buildings.

Words in This Pattern