Calculators

Refinance calculator

Already have a rate in writing from a lender, or curious what a different rate would mean? Enter your current loan and the proposed rate from your own quote. We never prefill a rate, because a calculator should not be the thing suggesting one.

Current loan balance

Remaining loan term (years)

Current interest rate (% p.a.) example rate only, enter the rate from your own loan statement

Proposed interest rate (% p.a.) deliberately blank, enter the rate from a quote you already have

Switching costs editable estimate, typically discharge plus mortgage registration fees

New loan term (years) optional, leave blank to keep your remaining term

Enter the proposed rate to compare

This calculator starts with the proposed-rate field empty on purpose. We don't prefill or suggest rates, because the right comparison is against a rate that's actually available to you, from a written quote or an offer you already hold.

Type the quoted rate into "Proposed interest rate" on the left and the comparison will appear here. Don't have a quote yet? That's exactly what we do all day, across 60+ lenders.

This calculator gives estimates for general information only. It is not credit advice or an offer of credit, and it does not take into account your objectives, financial situation or needs. Results depend on the figures you enter and the assumptions shown below, which you can edit. Actual amounts will vary with lender fees, charges and credit criteria. Consider your circumstances and seek advice before acting. Talk to us and we'll search for options available to you across 60+ lenders.

Extra important on this page: every rate in this calculator is a figure you entered yourself. The rates are not offers, quotes, advertised rates or suggestions from us, and nothing here is a recommendation to refinance, or not to. Whether a lender will approve a refinance, and on what terms, depends entirely on that lender's assessment of your circumstances at the time. Switching can also involve costs this calculator does not model, such as fixed-rate break costs, lenders mortgage insurance if the new loan is above 80% of the property value, and package or ongoing fees. Results are estimates for general information only and are not intended to be relied on when making a decision about a financial or credit product. Consider obtaining advice from a licensed professional before making financial decisions.

Assumptions (you can change these)

Every figure this calculator relies on is editable above: balance, remaining term, both rates, switching costs and the optional new term. The conventions below describe how the maths works.

Repayments are monthly, principal and interest, using the standard Australian lender display convention (the monthly amount is calculated from the monthly rate over the term in months). Both rates are assumed to stay the same for the whole term, which real rates never do, so long-range results are indicative only.

The headline comparison is a same-term basis: the proposed rate is measured over the same remaining term as your current loan, so the interest figures are like for like. If you enter a different new term, that result is shown as well, alongside the same-term result, never instead of it.

The switching-costs default of $700 is a rough allowance for a discharge fee plus mortgage registration fees, which vary by lender and state. Edit it to match your quote. It excludes fixed-rate break costs, lenders mortgage insurance, application or package fees, and any cashback offers.

Break-even is the first whole month where the accumulated monthly repayment saving covers the switching costs.

Interest savings two or more years out are also shown in today's dollars: each month's saving is discounted at the assumed inflation rate below.

Assumed inflation for today's-dollars figures (% p.a.)

Plain English

Reading a refinance comparison honestly

A refinance comparison has three honest questions in it. What does the new rate save each month? How long until that saving has paid back the cost of switching? And over the years you have left, does it genuinely leave you ahead?

The same-term trap

The classic mistake is comparing a 25-years-left loan against a fresh 30-year loan. The new repayment looks wonderfully low, but a lot of that drop comes from stretching the debt over five extra years, not from the rate. That's why this calculator always shows the same-term result, and warns you when a longer term means paying more interest overall even at a lower rate.

What the calculator can't see

Approval. A quoted rate only matters if the lender approves you for it. That depends on income, expenses, the property value and credit history at the time.
Break costs. Leaving a fixed rate early can trigger break costs that dwarf the standard switching fees.
LMI. If the new loan would be above 80% of your property's value, lenders mortgage insurance usually applies and changes the sums materially.
Features and fees. Offset accounts, package fees and cashbacks all move the real answer around.

The useful move is simple: get the whole picture before you switch. We compare your current loan against options from 60+ lenders, include the costs the calculator can't see, and tell you plainly if staying put is the better deal.

Book a free chat Free mortgage health check Payoff time calculator Amortisation calculator All calculators