Translation guide
A toilet that uses water to flush waste into a sewer or septic system. In Japanese, the most common term is 水洗トイレ, but other expressions exist depending on context.
Referring to a toilet that flushes with water, as opposed to a pit latrine or non-flushing toilet.
Standard term for a flush toilet. Combines 水洗 (water-washing) and トイレ (toilet).
この家には水洗トイレがあります。
This house has a flush toilet.
More formal or technical term, often used in official contexts or older texts. 便所 means toilet/lavatory.
公共施設には水洗便所が設置されています。
Flush toilets are installed in public facilities.
Descriptive phrase meaning 'flush-type toilet'. Useful when clarifying the type.
水洗式のトイレは清潔です。
Flush toilets are hygienic.
Specifying a sitting-type flush toilet, common in modern homes.
Western-style toilet, which is almost always a flush toilet. Often contrasted with 和式トイレ (Japanese-style squat toilet).
ホテルの部屋には洋式トイレがあります。
The hotel room has a Western-style toilet.
Focusing on the flushing mechanism or the act of flushing.
Literally 'water-washing', used in compounds or technical descriptions. Not a standalone word for toilet.
水洗機能が故障しました。
The flushing function broke.
In everyday conversation, トイレ usually implies a flush toilet unless specified otherwise. You can often just say トイレ without 水洗.
洋式トイレ (Western-style) is a sitting toilet, while 和式トイレ (Japanese-style) is a squat toilet. Both can be flush toilets, but 洋式 is more common in modern buildings.