Pro rata is an adverb or adjective, meaning in proportion. The term is used in many legal and economic contexts. It is sometimes spelled pro-rata, but this is technically a misspelling of the Latin phrase. In North American English this term has been vernacularized to prorated.
More specifically, pro rata means:
Pro rata has a Latin etymology, from , according to, for, or by, and , feminine ablative of calculated (rate or change).
Examples in law and economics include the following noted below.
When liability for a toxic tort or a defective product concerns many manufacturers, the liability under tort law is allocated pro rata.
Each of several partners "is liable for [her or his] own share or proportion only, they are said to be bound pro rata. An example ... may be found in the liability of partners; each is liable ... only pro rata in relation to between themselves."
When a debtor files for bankruptcy, and "the debtor is insolvent, creditors generally agree to accept a pro rata share of what is owed to them. If the debtor has any remaining funds, the money is divided proportionately among the creditors, according to the amount of the individual debts." "A creditor of an insolvent estate is to be paid pro rata with creditors of the same class."
A worker's part-time work, overtime pay, and vacation time are typically calculated on pro rata basis.
Under US Federal regulations, a government worker has the right such that: "When an employee's service is interrupted by a non-leave earning period, leave is earned on a pro rata basis for each fractional pay period that occurs within the continuity of employment."