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Loan Calculator

Calculate the monthly repayment, total interest and total cost of a personal, car or business loan, with a yearly amortisation breakdown.

Category
Calculators
Updated
Cost
Free · no sign-up

Monthly payment

$400.76

Over 60 payments.

Total interest$4,045.54
Total repaid$24,045.54
Interest share16.8%

Assumes a fixed rate and equal payments. Fees and insurance charged separately by the lender aren't included.

Yearly breakdown

Interest, principal and remaining balance by year
YearInterestPrincipalBalance
1$1,384$3,425$16,575
2$1,118$3,691$12,884
3$831$3,978$8,906
4$523$4,287$4,619
5$190$4,619$0

How a loan payment is calculated

Most consumer loans use level payments — the same amount every month for the whole term. The formula behind it:

payment = P × r ÷ (1 − (1 + r)^−n)

where P is the principal, r is the monthly interest rate (annual rate ÷ 12) and n is the number of payments. Each payment covers the interest accrued that month first; whatever's left reduces the balance.

Why early payments feel like they achieve nothing

Because interest is charged on the outstanding balance, the split between interest and principal shifts over the life of the loan. On a 20,000 loan at 7.5% over five years, the first payment is about 125 interest and 276 principal. The final payment is roughly 2 interest and 398 principal.

This is also why overpaying early is so effective. Money paid off the principal in year one removes every future interest charge that principal would have generated. The same overpayment in the final year saves almost nothing.

Interest rate versus APR

The interest rate is the cost of borrowing the money. The APR folds in mandatory fees — arrangement charges, broker fees, some insurance — and expresses the total as an annual percentage. Two loans with identical interest rates can have very different APRs.

Compare offers on APR, and check what the lender has included, because the rules differ by jurisdiction.

Term length is a real trade-off

Stretching a loan lowers the monthly payment and raises the total cost, often sharply. The monthly figure is what most people shop on, and it's the number lenders lead with. Look at total interest before deciding a longer term is affordable.

How to use the Loan Calculator

Three steps, no sign-up.

  1. Enter the amount you're borrowing

    Use the amount after any deposit or trade-in.

  2. Add the interest rate and term

    Use the APR if you have it — it includes most fees, so it's the fairer comparison.

  3. Compare total cost, not just the monthly figure

    A longer term lowers the monthly payment and raises the total interest, often by a lot.

Worked examples

A $20,000 car loan over 5 years at 7.5%

Inputs
$20,000 · 7.5% · 60 months
Result
$400.76 a month · $4,046 total interest

Frequently asked questions

What's the difference between interest rate and APR?
The interest rate is the cost of the borrowed money alone. APR folds in most mandatory fees, so it's the number to compare offers with.
How much does overpaying actually save?
A lot, early on. Extra payments in the first years come almost entirely off the principal, which removes all the interest that principal would have accrued.