pro rata

prorate | Business English

prorate
verb[ T ]
uk /ˌprəʊˈreɪt/us
ACCOUNTING
to calculate a cost, payment, or price according to the number of hours worked, how much of something has been used, etc. in relation to a larger number of hours worked, a larger amount of something used, etc.:
The bonuses for part-time employees should have been prorated based on their hours.

proration

noun[ U ]
The Fund and Investment Manager may share facilities common to each, with appropriate proration of expenses between them.

Examples of prorate

prorate
When items cannot be administered, scores can be prorated from the remaining items to an equivalent 10-item score.
The states argued that the special funds should have been prorated to the three levels of government, rather than assigned exclusively to the centre.
The second part can be prorated if the agreed upon samples are not forthcoming.
Missing data within a day's diary were accounted for by prorating the daily scores.
These budget totals are prorated over the fiscal year to derive monthly estimates.
We therefore prorated symptom counts for those missing one or two answers, and treated as missing counts for par ticipants with more than two answers missing.
Unlike other sections in the tax code which lack in allowing current deductions for most start-up expenses, section 195 allows a taxpayer prorate start-up expenditures over a 180-month period.
From
Wikipedia