per person; for each person
Used to indicate an amount, allocation, or cost for each individual. Commonly follows a quantity or noun.
参加費は一人当て三千円です。
The participation fee is 3,000 yen per person.
一人当ての予算は限られている。
The budget per person is limited.
Compound of 一人 (one person) and 当て (allocation, per). The reading ひとりあて is standard.