Difference between  割合 vs 率


割合 and 率 both mean ratio, rate, and percentage. What is the difference?




Neither means percentage. Percentage is one hundred times ratio or rate. The
Japanese word for it is `百分率`. Likewise, permillion is one million times ratio
or rate. The Japanese word for it is `百万分率`.

My impression is that `割合` and `ratio` are the general terms for a quantity
divided by another quantity (usually but not always of the same dimension).
`率` and `rate` are especially for cases where its lowness or highness is
connected to its preferred amount in an ideal situation. For example, `率` or
`rate` is used for `誤差~` or `error ~` because the ideal case would be zero. It
can be also used for `正解~` or `correctness ~` because the ideal situation will
be one. It is also used in `転送~` or `bit ~` because the larger the better.




Neither means percentage. Percentage is one hundred times ratio or rate. The
Japanese word for it is `百分率`. Likewise, permillion is one million times ratio
or rate. The Japanese word for it is `百万分率`.

My impression is that `割合` and `ratio` are the general terms for a quantity
divided by another quantity (usually but not always of the same dimension).
`率` and `rate` are especially for cases where its lowness or highness is
connected to its preferred amount in an ideal situation. For example, `率` or
`rate` is used for `誤差~` or `error ~` because the ideal case would be zero. It
can be also used for `正解~` or `correctness ~` because the ideal situation will
be one. It is also used in `転送~` or `bit ~` because the larger the better.

