Translation guide
The upper interior surface of a room, or a metaphorical upper limit.
The overhead surface inside a room.
Standard word for the ceiling of a room.
天井が高い部屋ですね。
This room has a high ceiling, doesn't it?
天井から雨漏りがする。
The ceiling is leaking.
A maximum limit, such as for prices, speed, or ability.
Upper limit or cap, used for numerical or abstract limits.
予算の上限は100万円です。
The budget ceiling is one million yen.
価格に上限を設ける。
Set a ceiling on prices.
Can also mean a metaphorical ceiling, especially in stock prices or ability.
Loanword from English 'cap', used in contexts like salary caps or interest rate caps.
サラリーキャップ制度
salary cap system
The maximum altitude an aircraft can reach, or the height of cloud base.
Used in aviation for service ceiling or cloud ceiling.
Often replaced by more specific terms like 上昇限度 (しょうしょうげんど) or 雲底 (うんてい) in technical contexts.
この飛行機の実用上昇限度は1万メートルだ。
The service ceiling of this aircraft is 10,000 meters.
天井 is primarily the physical ceiling of a room. It can be used metaphorically for limits, especially in stock markets or when something has peaked. 上限 is the standard word for an upper limit or cap in rules, budgets, etc.
株価は天井を打った。
The stock price has hit a ceiling.