Translation guide
In Japanese, expressing 'ratio' depends on whether you are comparing two numbers, describing a proportion, or talking about a rate. Common words include 割合 (わりあい) for general proportions, 比率 (ひりつ) for formal ratios, and 倍 (ばい) for multiples.
Expressing the relationship between a part and a whole, or a general proportion.
The most common and versatile word for 'ratio' or 'proportion'. Used in everyday conversation.
What is the ratio of men to women?
The proportion of international students in this class is high.
A more formal or technical term for 'ratio', often used in business, science, or statistics.
Please calculate the profit margin ratio.
A suffix meaning 'rate' or 'ratio', often used in compound words like 成功率 (success rate) or 失業率 (unemployment rate).
The unemployment rate is rising.
Expressing a specific ratio between two numbers, like 2:1 or 3:5.
Used to express a ratio of A to B. A and B are numbers.
The solution is mixed in a ratio of 1 to 3 of water and alcohol.
A more formal way to say 'the ratio of A to B'.
The ratio of students to teachers is 20 to 1.
Expressing how many times one quantity is compared to another.
Means 'times' or 'fold'. Used to say something is X times as much.
This room is twice as large as that room.
The price tripled.
Expressing a ratio per unit, like per person or per hour.
Attached to a unit to mean 'per'. Very common.
The cost per person is 5000 yen.
A speed of 100 km/h means traveling 100 km per hour.
割合 is the most general and colloquial. 比率 is formal and often used for precise numerical ratios. 率 is a suffix for rates (e.g., 確率 probability, 利率 interest rate).
The proportion of elderly people in this town is increasing.
The male-to-female ratio is almost 1 to 1.
The pass rate was 80%.
English 'ratio' is often used where Japanese would use 割合 or 倍. For example, 'the ratio of sugar to flour' is 砂糖と小麦粉の割合, not 比率 in casual cooking contexts. Also, 'price-performance ratio' is コストパフォーマンス or コスパ, not a direct translation.