Loan Repayment Calculator

By the Bureau of Wealth team Updated 15 September 2026

This calculator is general information, not financial advice. Check your own figures with the provider or a qualified adviser before acting on them.

Enter the amount, APR and term to see your monthly payment, the total interest you will pay, and how much sooner extra payments clear the loan.

Check the highlighted fields to see your results.

What this calculator assumes

The interest rate is fixed for the whole loan and interest is charged monthly on the balance still owed.
The APR you enter is divided by 12 to get the monthly rate. Lenders calculate APR to include some fees, so a quote can differ from this estimate by a few dollars a month.
Payments are made on time at the end of each month, with no payment holidays.
Fees charged separately, such as late fees, are not included. Neither are origination fees that are added to the amount borrowed rather than built into the APR.
Extra payments go straight to reducing the balance, and the lender charges no prepayment penalty.

Savings Goal Calculator
Could you save for this instead of borrowing? See how much to put aside each month to pay cash.

How the monthly payment is worked out

A fixed-rate loan is repaid in equal monthly installments. Each payment covers the interest that built up on the balance that month, and whatever is left over reduces the balance. Early on, most of each payment is interest. As the balance falls, the interest portion shrinks and more of each payment goes toward the amount you borrowed. This pattern is called amortization.

The calculator uses the standard amortization formula that banks and spreadsheets use. It takes the monthly rate (the APR divided by 12), the number of monthly payments (the term in years multiplied by 12) and the amount borrowed, and finds the single payment that brings the balance to exactly zero on the final month. It then runs through the loan month by month to add up the interest and build the year-by-year table and chart.

A worked example

Borrowing $10,000 at 5% APR over five years gives 60 monthly payments of $188.71. Across those five years you repay $11,322.74, so the loan costs $1,322.74 in interest. Spread the same loan over a longer term and the monthly payment falls, but you pay interest for more months, so the total cost rises.

You can check the payment in any spreadsheet with the formula =PMT(5%/12, 60, -10000), which returns 188.71.

What extra payments do

Any amount you pay above the required installment goes straight to the balance. A smaller balance means less interest the following month, so the effect compounds over time. On a $200,000 loan at 6% over 30 years, the required payment is $1,199.10 a month. Adding $200 a month clears it 108 months (nine years) early and saves about $79,800 in interest.

Before you pay extra, check your loan agreement for a prepayment penalty, and ask the lender to apply the extra amount to the principal rather than to future payments.

Comparing loan offers

The Consumer Financial Protection Bureau recommends comparing loans by APR rather than by interest rate, because the APR includes certain fees charged when the loan is made. Two loans with the same interest rate can have different APRs if one charges higher fees. Run each offer through the calculator with its APR and the same term to compare the monthly payment and total cost side by side.

If the loan is for something you could wait for, the savings goal calculator shows how much you would need to put aside each month to pay cash instead, and what interest you would earn rather than pay.

Frequently asked questions

What is the difference between the interest rate and the APR?

The interest rate is the cost of borrowing the money. The APR adds certain fees charged by the lender, such as origination charges, and expresses the total as a yearly rate. Lenders must show you the APR, which makes it the fairer number for comparing offers.

Why is so much of my early payment interest?

Interest is charged on the balance you still owe. At the start that balance is at its highest, so the interest portion of each payment is largest. It falls every month as the balance goes down.

Is a longer loan term cheaper?

A longer term lowers the monthly payment but usually raises the total cost, because interest is charged for more months. Try the same loan over three and five years in the calculator to see the difference in total interest.

Does paying extra always save money?

Paying extra reduces the balance and therefore the interest charged, as long as your lender does not charge a prepayment penalty and applies the extra amount to principal. Keeping an emergency fund first is usually sensible, so an unexpected bill does not push you onto a credit card.

Can I use this for a car loan?

Yes, for a simple interest auto loan with a fixed rate. Enter the amount you are financing after your down payment and any trade-in, the APR from the dealer or lender, and the term in years.

Sources

Figures come from institutions millions of people rely on. How we keep calculators accurate.