Loan Calculator
Enter a loan amount, interest rate and term to see your monthly payment, total interest, total paid and a full amortization schedule. Free, instant, private.
Amortization schedule (click a year to expand months)
| Year | Principal | Interest | Total paid | Balance |
|---|
The repayment formula, written out
The monthly repayment comes from the standard amortising loan equation:
Payment = P x r / (1 - (1 + r)-n)
P is the amount borrowed. The letter r is the monthly rate, which this page gets by dividing the annual rate by 100 and then by 12. The letter n is the number of monthly payments, the term in years multiplied by 12 and rounded to a whole number. If you enter a rate of zero, the page skips the formula and just divides the principal by the number of months.
Note that the annual rate is divided by 12 rather than converted using a twelfth root. That is the same convention Australian lenders use when quoting a nominal annual rate on a monthly-repayment loan, so the figure lines up with a bank's own schedule.
Worked example: a $450,000 loan
Borrow $450,000 at 6.2 per cent over 30 years.
The monthly rate is 0.062 / 12 = 0.00516667, and n = 360 payments.
Payment = 450,000 x 0.00516667 / (1 - 1.00516667-360) = $2,756.11 a month.
Over the full term that is 360 x 2,756.11 = $992,199.74 paid, of which $542,199.74 is interest. The interest bill is larger than the deposit on most houses and slightly larger than the amount borrowed.
The first repayment is mostly rent on the money: $2,325.00 of it is interest (450,000 x 0.00516667) and only $431.11 reduces the balance. Five years in, after 60 repayments totalling $165,366.60, the balance has only fallen to about $419,766, because roughly $135,000 of what you paid went to interest.
What a shorter term actually costs and saves
Change the term field to 25 and leave everything else alone. The repayment rises to $2,954.62, an extra $198.51 a month. Total interest falls to $436,385.83.
That is $105,813.91 less interest for an extra $198.51 a month. Running that comparison before you sign is usually more valuable than shaving a few points off the advertised rate, and it takes about four seconds in the term box.
Australian loans and the gaps in this model
Most Australian home loans are either variable or fixed for an introductory term of one to five years, after which they revert to a variable rate. This calculator assumes one fixed rate for the entire term, so for a variable loan it answers the question "what if the rate never moved again", which it will.
A practical way to use that limitation is as a stress test. Run your loan at the rate you have been offered, then run it again two or three percentage points higher and look at the repayment figure. If that second number would break your budget, you have learnt something useful.
Repayments here are monthly only. Many Australian borrowers pay fortnightly, and lenders commonly set a fortnightly amount at half the monthly figure. Because there are 26 fortnights in a year rather than 24, that quietly pays about one extra monthly repayment annually and shortens the loan. On the $450,000 example, half of $2,756.11 is $1,378.06, paid 26 times is $35,829.44 a year against $33,073.32 for monthly. The tool does not model that schedule, so treat it as an extra you would need to work out separately.
Also missing: lenders mortgage insurance, application and ongoing fees, stamp duty, council rates, offset account balances, redraw, and any lump sum you throw at the principal. Every one of those changes the real cost. The figures here are general information and not financial advice or a credit quote. A licensed mortgage broker or financial adviser can look at your full position; a web page cannot.
Reading the schedule
Each year row sums the twelve repayments inside it and shows the balance at the end of that year. Click a row to expand the individual months. The final month is handled slightly differently: the principal portion is set to whatever balance remains so the loan closes at exactly zero, which can leave the last row a few cents off the regular repayment. The headline total is calculated as the repayment multiplied by the number of payments.
Related tools
To see the same compounding maths working for you instead of against you, try the Compound Interest Calculator. For deposit sums, LVR and rate change sums, the Percentage Calculator is quicker. To count the months remaining on a fixed rate period, use the Date Difference Calculator.
Questions borrowers ask
Why is my bank's repayment a few dollars different?
Usually rounding or fees. Lenders often round the repayment up to the nearest cent or dollar, and many add a monthly account fee to the direct debit. Some also calculate interest on daily balances rather than a flat monthly period, which shifts the split by small amounts.
Can I model extra repayments or an offset account?
Not in this tool. It assumes the scheduled repayment is paid, no more and no less, for the entire term. Extra repayments would reduce both the interest and the term, so the totals shown are a ceiling rather than a prediction.
Does the amount include a deposit, stamp duty or LMI?
No. Enter the amount you are actually borrowing after your deposit. Upfront costs such as stamp duty and lenders mortgage insurance are separate, although LMI is sometimes capitalised into the loan, in which case include it in the amount.
Does this work for a car or personal loan?
Yes. The formula is the same for any loan repaid in equal monthly instalments at a fixed rate. Enter the term in years, so a four-year car loan is 4 and a six-month term is 0.5.
Are my loan figures sent anywhere?
No. All of this arithmetic happens inside your browser, and none of the amounts you type are transmitted or saved.