noun, noun, used as a suffix
A part or share of something, often used with possessive or modifier: 私の分, あなたの分, 今日の分.
これはあなたの分です。
This is your share.
今日の分の仕事は終わった。
I've finished today's portion of work.
noun, used as a suffix
Suffix-like use after a quantity or time expression to mean 'worth of' or 'enough for'. Common with days, people, etc.
3日分の食料を買った。
I bought three days' worth of food.
これは一人分の量です。
This is an amount for one person.
noun
one's means; one's place; one's social position
Refers to one's social standing, means, or lot in life. Often used in set phrases like 分をわきまえる (know one's place).
彼は自分の分をわきまえている。
He knows his place.
分に過ぎた望みは持たないほうがいい。
You shouldn't have ambitions beyond your station.
noun
One's role or duty in a situation. Often used in expressions like 分を尽くす (do one's part).
自分の分をしっかり果たしなさい。
Do your part properly.
noun
condition; state of affairs; extent
Used in expressions like この分では (at this rate) or その分 (to that extent). Describes a situation or degree.
この分では明日は雨だろう。
At this rate, it will rain tomorrow.
その分、値段も高い。
To that extent, the price is also high.
noun, adverb
in proportion to; just as much as; to the same degree
Adverbial use indicating proportionality. Often follows a noun or clause with に: 努力した分だけ (just as much as one worked hard).
努力した分だけ結果が出る。
Results come in proportion to the effort you put in.
値段が高い分、品質も良い。
The quality is good to the same degree that the price is high.
noun, used as a suffix
Suffix-like use indicating the content or percentage of a substance, e.g., アルコール分 (alcohol content).
この酒はアルコール分が15%だ。
This sake has an alcohol content of 15%.
noun, used as a suffix
equivalent to; like a
Suffix-like use meaning 'equivalent to' or 'like a', often in compounds such as 兄貴分 (someone like an older brother).
See also: 兄貴分
彼は私にとって兄貴分のような存在だ。
He is like an older brother to me.
部分 means a part or section of a whole, while 分 often refers to a share, portion, or amount allocated to someone or something.
割合 means ratio or proportion, while 分 can express proportionality in a more adverbial or suffix-like way.
The kanji 分 originally means 'divide' or 'part'. The reading ぶん is the on'yomi and is used in many compound words. The exact historical derivation of the various noun and suffix uses is uncertain, but they all stem from the core idea of a divided portion or share.