Loan Repayment Comparison Calculator

How to use it

Enter the loan amount, annual rate, term and grace period.
Compare the first monthly payment and total interest on the three cards. Select a card to emphasize that method on the chart.
If needed, add a monthly extra payment or a one-time prepayment in the advanced settings, then check the Prepayment effect chart and the monthly/yearly schedule (CSV download).

Examples

$500,000 at 4% for 30 years

The cards show the initial monthly burden and total interest side by side. Equal principal normally costs less interest but starts with a higher payment.

Details

This calculator builds a month-by-month cash-flow schedule for three common repayment structures. Equal payment uses one rounded installment after any grace period. Equal principal repays a similar amount of principal each month, so its payment normally falls over time. A bullet loan pays interest during the term and repays the remaining principal in the final month. Monthly interest is the previous balance multiplied by the annual percentage rate divided by twelve, with fractions below the smallest currency unit discarded.

A grace period is included within the total loan term. During grace, only interest is due, so the principal does not fall and the remaining repayment period becomes shorter. The trend chart omits the final principal lump sum from the bullet line so that its ordinary interest payments remain comparable with the other two methods. The result cards and monthly schedule still include the actual final payment.

The optional prepayment scenario applies one extra principal payment immediately after the regular payment in the chosen month. Shorten term keeps the scheduled payment pattern until the balance reaches zero; reduce payment recalculates payments over the remaining term. The estimated fee declines toward the entered exemption month. Lenders may use daily interest, different rounding, variable rates, or different fee formulas, so use this as a comparison rather than a quote. A monthly extra payment is applied right after each regular payment from month 1; the loan ends in the month the balance reaches zero.

Frequently asked questions

Which method usually has the lowest total interest?

With the same positive rate and term, equal principal usually has the lowest interest because the balance falls faster, but its early payments are higher.

Why is the bullet loan spike missing from the chart?

The chart shows its regular interest payment so the three trends remain readable. The card and schedule include the principal due in the final month.

How does a grace period change the result?

The balance does not fall during grace. With the same total term, later payments become heavier and total interest generally rises.

When is the prepayment fee waived?

In this estimate, the fee reaches zero at the exemption month you enter. Check your lender's actual contract.