Translation guide
The quality of being fair, sensible, or based on good judgment. In Japanese, this concept is expressed through various words and phrases depending on whether you mean fairness, logical soundness, appropriateness, or moderation.
Expressing that something is fair, just, or equitable.
Refers to the validity or appropriateness of a decision, price, or argument. Often used in formal contexts.
その判決の妥当性について議論が続いている。
There is ongoing debate about the reasonableness of the verdict.
Emphasizes logical consistency and rationality. Often used in economic or philosophical contexts.
彼の提案には合理性が欠けている。
His proposal lacks reasonableness.
Literally 'the logic passes through', meaning something is reasonable or makes sense. Common in everyday speech.
彼の言い分は筋が通っている。
His argument is reasonable.
Refers to legitimacy or justifiability, often in legal or ethical contexts.
その要求の正当性を認める。
I acknowledge the reasonableness of the demand.
Describing something that is sensible, practical, or not extreme.
An adjective meaning appropriate or reasonable, often used for prices, decisions, or actions.
その値段は妥当だと思う。
I think that price is reasonable.
Means 'conforms to reason', indicating something is logical and sensible.
彼の判断は理にかなっている。
His judgment is reasonable.
Literally 'without strain', meaning reasonable, moderate, or not excessive. Often used for schedules, demands, or expectations.
無理のない計画を立てましょう。
Let's make a reasonable plan.
Often used for prices meaning 'affordable' or 'reasonable', but can also mean 'handy' or 'suitable'.
Expressing that an amount, degree, or action is moderate and not extreme.
A noun/adverb meaning 'moderation' or 'reasonable degree'. Often used in advice to not overdo something.
お酒はほどほどにしてください。
Please drink in moderation (be reasonable with alcohol).
Means 'moderate' or 'proper amount', often used for exercise, drinking, etc.
Means 'commonsensical' or 'within the bounds of common sense', implying reasonableness.
The English noun 'reasonableness' is rarely translated directly as a single Japanese noun. Instead, Japanese speakers express the idea through adjectives like 妥当な, 合理的な, or phrases like 筋が通っている. Using a noun form like 合理性 or 妥当性 is possible but often sounds formal or technical.
妥当 (datō) means 'reasonable' in the sense of 'appropriate under the circumstances', while 適切 (tekisetsu) means 'suitable' or 'proper'. 妥当 is closer to 'reasonableness' when judging a decision or price; 適切 is more about suitability for a purpose.
この件についてのあなたの妥当な判断に感謝します。
I appreciate your reasonableness in this matter.
Using 妥当な判断 (reasonable judgment) instead of a noun
I'm looking for a reasonably priced hotel.
Moderate (reasonable) exercise is good for your health.
Please make a reasonable judgment.