日本語

「◯◯パーセント」と「◯割◯分」は両方とも「◯◯％」を意味しますが、どちらを使うのが自然ですか。「◯割◯分」という表現を使いたいのですが、使う前にその言い方が九分九厘使わないものではないことを確かめた方がいいと思ったので、質問します。

English

Both ◯◯パーセント and ◯割◯分 can mean ◯◯％. Which is the natural choice? I wanted to use ◯割◯分 but I wanted to be sure that it is not an expression that is not used anymore so I prefer to ask before using it.

• 「九分九厘」のところを変えてしまいましたが、間違って解釈していたらすみません・・・ Apr 15, 2016 at 12:53
• 別にコメントしましたが、この場合「九割九分」か「九分九厘」が、共に計算上99%を表すidiomです。「九割九部九厘」は論理的には間違いではないでしょうけど、あまり使いません。 Apr 15, 2016 at 14:43
• @naruto ・・・ということは「九分九厘」に戻したほうがいいのでしょうか。。。うーん、どうしたらいいかわかりません。。すみません！ Apr 15, 2016 at 14:45
• 「里」は誤字なので、九分九厘にすれば大丈夫かと。ややこしいですねえ…。 Apr 15, 2016 at 14:48

If you only need one digit precision, for example 4割 is equally common to 40パーセント. In hasty conversations, パーセント is often shortened to パー (eg. 40パー).

If you need two digits precision, 4割5分 is no longer common today, and 45パーセント is the normal choice.

Today, ○割○分(○厘) is used only in the following cases:

• in a fixed expression 九割九分 (=almost certainly/always)
• in baseball contexts to describe batting average of players (eg., ".321" is "3割2分1厘")
• rarely in financial contexts to show interest rates

〇割 is commonly used. For example, この服を定価の一割安くします(I take ten percent off the price of this piece of clothing.), 私の学校の二割の生徒は、英語が話せる(Twenty percent of the students in my school can speak English).

However, I think 〇分 which means percent isn't very common. For example, we don't say now "Five percent of the students in my school are Japanese" like 私の学校の五分の生徒は日本人だ.

• "1分 = 1%" is a common misunderstanding which is believed even by many native Japanese speakers. Actually, 分 always means 10% (hence the expressions like 八分咲き, 七分袖, 五分五分, 九分がた完成, 38度5分の発熱, 九分九厘 (=99%)). 分 appears to mean 1% only when it follows 割, because 割 itself means 10%, and 分 stands for "1割の10%" in such a case. See this entry. Apr 15, 2016 at 14:34
• @naruto I believed that 九分九厘 = 0.99 = 99/100 = 99% because 分 can mean 10^{-1} and 厘{りん} can mean 10^{-2}. So 分 means 1/10 which is 10%. Apr 15, 2016 at 15:11