Compound Interest Loan Calculator

The loan calculators on this page require a browser that supports JavaScript and tables (eg. Netscape version 2 or higher or Microsoft Internet Explorer version 3 or higher).

There calculators for 3 different purposes:

There is also a discussion about the calculators

(For a "low start" loan where the initial interest rate is lower, first use the loan balance calculator to find the balance at the end of the low interest period, then use the loan repayment or loan time calculator for calculations on the remainder of the loan, using the reduced value for the initial loan amount.)
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Calculate Repayments for normal loan
Check here if repayments start half a month after getting loan (instead of usual time of 1 month)
Loan Amount % Interest Years to Repay Monthly Repayments.
Enter values in first 3 of the fields above, then click once on the button.
The results of this calculator should be used as a guide only, check with your lending institution. The calculator's author accepts no responsibility for any actions based on the use of this calculator.

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Calculate Time to repay a normal loan
Check here if repayments start half a month after getting loan (instead of usual time of 1 month)
Loan Amount % Interest Monthly Repayments. Years to Repay
Enter values in first 3 of the fields above, then click once on the button.
The results of this calculator should be used as a guide only, check with your lending institution. The calculator's author accepts no responsibility for any actions based on the use of this calculator.

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Calculate Balance of a normal loan after some time
Check here if repayments start half a month after getting loan (instead of usual time of 1 month)
Loan Amount % Interest Monthly Repayments. Years of Repaying Amount Remaining
Enter values in first 4 of the fields above, then click once on the button.
The results of this calculator should be used as a guide only, check with your lending institution. The calculator's author accepts no responsibility for any actions based on the use of this calculator.

About the calculators:
  1. To do calculations for a "low start" loan where the initial interest rate is lower, first use the loan balance calculator to find the balance at the end of the low interest period, then use the loan repayment or loan time calculator for calculations on the remainder of the loan, using the reduced value for the initial loan amount.
  2. The calculator can show the dramatic effects of making extra repayments early in the loan, provided that the loan is such that additional repayments reduce the balance that the interest is calculated on. For example, borrowing $100,000 at 10% over 30 years needs monthly repayments of very close to $877. However, if the borrower makes only one additional payment of $877 at the very start of the loan, this will reduce the time taken to repay the loan by over a year and a half, check this by using the calculator to see the effect of borrowing $877 less and repaying at the same rate of about $877 per month.
  3. Repaying loans fortnightly rather than monthly is a good idea if you get paid fortnightly and make the loan repayments as soon as you get paid. But people getting paid monthly are better off paying monthly as soon as they get paid. The idea in both cases is to use your money to reduce the amount you owe at the earliest opportunity.
  4. The loan calculations use formulae that can be seen if the source is viewed. They were obtained using calculus, assuming continuous repayment and interest accumulation.
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Copyright © 1997,2000 Howard Houliston
Last updated 12 Jan 2000