Javascript Rule of 78 Rebate Calculator - Equal instalments

This calculator will work out the rebate and settlement figures for loans with regular, equal monthly or weekly instalments and also for loans where payments are made at the start or end.  Please see the notes below for more information.

To use the calculator, fill in the figures in the boxes marked '*', select the button for the repayment frequency and then click on the 'Calculate' button to display the results in the final two boxes.  Click on the 'Reset' button to clear the calculator for a new calculation.

* Amount of credit (£):
* Amount of initial payment (£):
* Amount of regular repayments (£):
* Number of regular repayments:
* Additional final repayment (£):
* Time of settlement (months/weeks):
Repayment frequency: Months Weeks
Statutory rebate (£):
Settlement figure (£):

Coded in JavaScript and HTML by Brian Stewart, v1.1 December 2001


  • This calculator handles calculations under the rules in the 1983 Rebate on Early Settlement Regulations, for newer loans you should use the method in the 2004 Early Settlement Regulations.

  • The result given for the settlement figure assume that all payments up to and including that due on the settlement date are also made. In practice you will have to pay the settlement figure plus the payment due on the settlement date to settle. The lender may give you a figure which also includes any other payments due before the settlement date. If you are in arrears, the missed payments will have to be made up and other charges may be payable too.

  • If you ask the lender for a settlement statement (strictly, you should do that in writing) , the settlement date used is the date of the next repayment due 28 days after they get your request (unless you give a later date). For example: if repayments are due on the 15th of every month and you ask for a settlement figure on the 20th of January, the 28-day period will go beyond the 15th of February and the date used will be the 15th of March.

  • The rules allow the lender to 'weight' the calculation by working out the rebate assuming you settle later - for loans longer than five years a one month weighting can be used and for shorter loans two months. The calculator adds this automatically and displays '+1' or '+2' in the Time of Settlement box. As the weighting is in months, for weekly loans '+4' and '+8' weeks are added instead.

  • The rules allow the use of a method called the 'Rule of 78' to calculate the rebate, unless the loan is repaid in a single amount. If the Additional Final Repayment is equal to, or more than, Amount of Credit, the calculator assumes that the loan is being repaid in a single amount and uses the 'Pro-rata' method instead.