効 — “effect / effective” in Japanese

Grade 5こう, き

Radical ⼒ · radical 19 The building block this kanji is filed under

“effect / effective” in Japanese is 効, read kou, ki (こう, き). It is a Grade 5 Kyōiku kanji, taught in year 5 of Japanese elementary school, and appears in words such as 効果 (effect).

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What does 効 mean?

Full details, readings & example

Kanji	効
Meaning	effect / effective
Readings	こう, き
Grade	Grade 5 (Hard)
Curriculum	Kyōiku kanji · Japanese elementary school
Example	効果 (effect)

How to read 効

効 is read kou (こう) or ki (き) depending on the word.

Words with 効

効果こうか

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Kanji read the same way as 効

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Updated: 2026-08-28