Translation guide
The English preposition 'per' is used to express rates, ratios, or units. In Japanese, this is most commonly expressed with the particle 〜につき (ni tsuki) or the suffix 〜当たり (atari). The choice depends on formality and context.
Expressing a quantity or frequency in relation to a unit (e.g., per day, per person, per hour).
Attached to a counter or unit noun. Common in formal, written, or business contexts. Often used for rules, fees, or official rates.
駐車料金は1時間につき500円です。
The parking fee is 500 yen per hour.
Please take this medicine three times per day.
Attached to a counter or unit noun. Slightly less formal than 〜につき, but still very common in both speech and writing. Often used in everyday contexts.
1人当たりの費用は3000円です。
The cost per person is 3000 yen.
この車は1リットル当たり20キロ走ります。
This car runs 20 kilometers per liter.
Means 'every' or 'per' when emphasizing regular intervals or each occurrence. Often used for time or distance intervals.
このバスは10分ごとに来ます。
This bus comes every 10 minutes (per 10 minutes).
1メートルごとに印をつけてください。
Please make a mark per meter (every meter).
Used in formal or technical contexts to mean 'per' when comparing a quantity to a unit. Often seen in statistics or academic writing.
人口1000人に対して医師の数は2人です。
There are 2 doctors per 1000 people.
Meaning 'in accordance with' or 'as stated by' (e.g., as per instructions, per your request).
Literally 'in the way of'. Used to mean 'as per' when following instructions or a model.
指示の通りに作業を進めてください。
Please proceed with the work as per the instructions.
Means 'according to' or 'in compliance with'. Slightly more formal than 〜の通りに.
規則に従って処理します。
We will process it as per the regulations.
Means 'based on' or 'as per'. Common in business or legal contexts.
契約に基づいて支払いを行います。
We will make the payment as per the contract.
Both mean 'per', but 〜につき is more formal and often used in official notices, rules, or written instructions. 〜当たり is slightly more colloquial and common in everyday conversation. In many cases they are interchangeable, but 〜につき can sound stiff in casual speech.
The English word 'per' is sometimes borrowed as パー (paa) in compound terms like キロメートルパーアワー (kilometers per hour), but this is not a general-purpose translation. Using パー outside of set loanwords will sound unnatural.
制限速度は時速60キロです。
The speed limit is 60 kilometers per hour.
Often expressed with 時速 (per hour) as a prefix, not a separate 'per' word.
一泊いくらですか？
How much does it cost per night?
Using 一泊 (one night's stay) implies 'per night' without a separate particle.