Enter the number of days used and the total days in the period into the calculator to determine the prorate factor. This calculator helps in adjusting payments or costs based on the actual days used.

Prorate Factor Formula

The following formula is used to calculate the prorate factor.

PF = DU / TD

Variables:

  • PF is the prorate factor
  • DU is the number of days used
  • TD is the total days in the period

To calculate the prorate factor, divide the number of days used by the total days in the period.

What is a Prorate Factor?

A prorate factor is a fraction that represents the proportion of a full period that has been used or consumed. It is commonly used in financial contexts to adjust payments or costs based on the actual days used compared to the total days in a billing cycle or contract period. This ensures that charges are fair and proportional to the time or resources consumed.

How to Calculate a Prorate Factor?

The following steps outline how to calculate the Prorate Factor.


  1. First, determine the number of days used (DU).
  2. Next, determine the total days in the period (TD).
  3. Next, gather the formula from above = PF = DU / TD.
  4. Finally, calculate the Prorate Factor (PF).
  5. After inserting the variables and calculating the result, check your answer with the calculator above.

Example Problem : 

Use the following variables as an example problem to test your knowledge.

number of days used (DU) = 15 days

total days in the period (TD) = 30 days