Mortgage calculator Australia
Calculate your home loan repayments and see how extra payments can save you thousands in interest and years off your mortgage. Weekly, fortnightly, and monthly options.
Principal you intend to borrow.
Headline rate — comparison rate may differ.
Interest-only repayments switch to principal and interest after the selected period.
Adds on top of every scheduled payment; reduces total interest.
Amortisation schedule
| Period | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $3,062.34 | $479.01 | $2,583.33 | $499,520.99 |
| 2 | $3,062.34 | $481.49 | $2,580.86 | $499,039.50 |
| 3 | $3,062.34 | $483.97 | $2,578.37 | $498,555.53 |
| 4 | $3,062.34 | $486.47 | $2,575.87 | $498,069.05 |
| 5 | $3,062.34 | $488.99 | $2,573.36 | $497,580.07 |
| 6 | $3,062.34 | $491.51 | $2,570.83 | $497,088.55 |
| 7 | $3,062.34 | $494.05 | $2,568.29 | $496,594.50 |
| 8 | $3,062.34 | $496.61 | $2,565.74 | $496,097.89 |
| 9 | $3,062.34 | $499.17 | $2,563.17 | $495,598.72 |
| 10 | $3,062.34 | $501.75 | $2,560.59 | $495,096.97 |
| 11 | $3,062.34 | $504.34 | $2,558.00 | $494,592.62 |
| 12 | $3,062.34 | $506.95 | $2,555.40 | $494,085.67 |
| 355 | $3,062.34 | $2,969.11 | $93.24 | $15,077.22 |
| 356 | $3,062.34 | $2,984.45 | $77.90 | $12,092.78 |
| 357 | $3,062.34 | $2,999.87 | $62.48 | $9,092.91 |
| 358 | $3,062.34 | $3,015.36 | $46.98 | $6,077.55 |
| 359 | $3,062.34 | $3,030.94 | $31.40 | $3,046.60 |
| 360 | $3,062.34 | $3,046.60 | $15.74 | $0.00 |
Each mortgage repayment consists of two parts: principal (paying down the loan) and interest (the cost of borrowing). In the early years, most of your payment goes to interest. As the loan balance decreases, more goes to principal.
Principal & Interest (P&I)
The standard loan type. Each payment reduces your loan balance and covers interest. Most owner-occupier loans are P&I.
Interest Only (IO)
You only pay interest for a set period (usually 1–5 years). The loan balance doesn't decrease. Often used by investors.
Making extra repayments is one of the most effective ways to pay off your mortgage faster. On a $500,000 loan at 6% over 30 years:
Extra $100/month
~$57,300
interest saved · 2.5 years early
Extra $200/month
~$103,100
interest saved · 4.5 years early
Extra $500/month
~$199,500
interest saved · 9 years early
Frequency and annual repayment amount are separate choices. A standard lender-calculated schedule can still run for the full term; the faster method deliberately pays the equivalent of one extra monthly repayment each year.
Setting your fortnightly repayment to exactly half your monthly amount — rather than a quarter of an annual figure — is the trick that makes fortnightly repayments save real money. Because there are 26 fortnights in a year, you end up making the equivalent of 13 monthly payments instead of 12, with the extra payment going straight to principal.
Monthly (12/yr)
$3,062.34
30 years · $602,444 total interest
Half-monthly fortnightly (26/yr)
$1,531.17
~24.4 years · ~$469,574 total interest
On a $500,000 loan at 6.2% over 30 years, paying half your monthly repayment every fortnight pays the loan off roughly 5.6 years sooner and saves about $132,870 in interest compared with the standard monthly schedule. See our fortnightly vs monthly repayments guide for the full breakdown, including why some lenders' "fortnightly" default doesn't actually deliver this saving.
Every mortgage repayment splits between interest and principal, and that split changes across the life of the loan. In the early years, most of each repayment covers interest on the large outstanding balance — on a $500,000 loan at 6.2%, the very first monthly repayment of $3,062.34 is $2,583.33 interest and just $479.01 principal.
As the balance falls, the interest portion of each repayment shrinks and the principal portion grows, until the two cross over — typically past the halfway point of a 30-year term. This is why extra repayments made early in the loan have an outsized effect: every dollar of extra principal in year one stops accruing interest for the remaining 29 years.
Run your own numbers and see the full month-by-month interest/principal split below the calculator above, or read our amortisation schedule guide for a worked walkthrough.
Indicative monthly principal & interest repayments at 6.2% p.a. over a 30-year term, for common loan sizes:
| Loan amount | Monthly repayment |
|---|---|
| $300,000 | $1,837 |
| $500,000 | $3,062 |
| $750,000 | $4,594 |
| $1,000,000 | $6,125 |
Based on the reference rate in the calculator above (6.2% p.a., last reviewed 2026-05-02). Your actual rate depends on your lender, LVR, and loan type — use the calculator to model your own figures.
How is mortgage repayment calculated?
How does the interest-only calculation work?
Do weekly or fortnightly repayments automatically save interest?
What is a comparison rate?
What is an offset account?
Should I fix my interest rate?
Should I pay my mortgage fortnightly or monthly?
What is an amortisation schedule?
Tax Accuracy & Sources
Estimates principal-and-interest repayments using the standard PMT formula. For interest-only loans it models an initial IO period followed by principal-and-interest repayments over the remaining original term. Assumes a constant rate and does not account for lender fees, comparison rates, lenders mortgage insurance, offset accounts, or redraw facilities.