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:
- In proportionality to some factor that can be exactly calculated
- To count based on amount of time that has passed out of the total time
- Proportional ratio
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."
Worker's pay and benefits
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."
The American Federation of Teachers (AFT), a US labor union, argues that all part-time or adjunct instructors should get pro-rata pay for teaching college courses. This is an important issue, as of 2010, for part-time faculty.
In banking, "Pro-rating also refers to the practice of applying interest rates to different time frames. If the interest rate was 12% per annum, you could pro-rate this number to be 1% a month (12%/12 months)." 
In insurance, pro rata is used to determine risk based on the time the insurance policy is in effect. It may also be used to describe proportional liability when more than one person is responsible for a loss or accident.
Insurance cancellation method
Calculation of return premium of a cancelled insurance policy is often done using a cancellation method called pro rata. First a return premium factor is calculated by taking the number of days remaining in the policy period divided by the number of total days of the policy. This factor is then multiplied by the policy premium to arrive at the return premium. Traditionally this has been done manually using a paper wheel calculator. Today it is normally done using an online wheel calculator.
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- Employee Retirement Income Security Act
- Legal liability
- Pro rata cancellation
- Pro rata condition of averages
- Farlex's The Free Dictionary Article is available to subscribers only.
- "What is Pro Rata? definition and meaning". InvestorWords.com.
- Ehrlich, Eugene (1987) . Amo, Amas, Amat and More. New York: Harper Row. p. 233. ISBN 0-06-272017-1.
- Investopedia web site. Accessed May 29, 2008.
- The Free Dictionary. Accessed May 29, 2008.
- "Manufacturer 2007 Pro Rata Share Responsibility(sic) for Orphan Waste for Maine Household Televisions Computer Monitor Recycling Program" (PDF). Maine.gov. Maine Department of Environmental Protection. November 2006. Archived from the original (PDF) on 2011-06-05. Retrieved 2016-08-30.
- ClickDocs UK Legal web site (quote marks changed to italics for clarity).
- "Pro Rata". law.jrank.org.
- "WWLIA legal web site". Archived from the original on 2007-10-06.
- John Steven Niznik, Pro Rata, at Job Search Tech web site.
- "TheSite.org web page about pro-rata payment for part-time work". Archived from the original on 2007-06-19.
- US Department of Commerce Office of Human Resources Management official web site, citing 5 CFR 630.204.
- "AFT web site".[permanent dead link]
- California Part-time Faculty Association official web site page regarding pro-rata pay Archived 2007-09-30 at the Wayback Machine
- "Association of Secondary Teachers Ireland official web site page regarding pro-rata pay". Archived from the original on 2007-08-28.
- NASUWT web site Archived 2007-10-09 at the Wayback Machine Holiday is used here in the British sense of the American vacation.
- "Tasmanian Government official web site". Archived from the original on 2007-04-04.
- "Long Service Leave Guide" (PDF). WST.Tas.gov.au. Tasmania Department of Justice and Industrial Relations. February 2002. Archived from the original (PDF) on 2006-09-27. Retrieved 2016-08-30.
- Tasmanian Legislation online official web site
- AVC.com web site. Accessed August 20, 2015.
- InsuranceZA web site
- "wheel-calculator.com". www.wheel-calculator.com.
- 14 CFR § 61.113 (c)