Mortgage calculator

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.

P&I and interest-only Extra repayment savings Amortisation schedule

01 —INPUTS

Loan amount (AUD)

Principal you intend to borrow.

Annual interest rate (%)

Headline rate — comparison rate may differ.

Loan term (years)

Repayment frequency

Extra payment per period (AUD, optional)

Adds on top of every scheduled payment; reduces total interest.

02 —RESULTS

Repayment per monthly period3,062.34

Total interest over loan602,444.16

Total paid (principal + interest)1,102,444.16

Payoff time30.1 years (361 monthly periods)

03 —BREAKDOWN

Amortization 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
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
361	0.00	0.00	0.00	0.00

How mortgage repayments work

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.

The power of extra repayments

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

~$45,000

interest saved · 4 years early

Extra $200/month

~$80,000

interest saved · 7 years early

Extra $500/month

~$140,000

interest saved · 12 years early

Weekly vs fortnightly vs monthly

A more frequent repayment schedule can save you money without increasing your monthly budget.

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Monthly — 12 payments per year — the standard.

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Fortnightly — 26 payments per year, equivalent to 13 monthly payments. The extra payment goes directly to principal.

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Weekly — 52 payments per year — same net effect as fortnightly but with smaller individual amounts.

FAQ

How is mortgage repayment calculated?

Mortgage repayments are calculated using the PMT formula: P × (r(1+r)^n) / ((1+r)^n - 1), where P is the principal, r is the periodic interest rate, and n is the total number of payments. This gives you the fixed payment needed to pay off the loan over the term.

Should I make weekly or monthly repayments?

Weekly or fortnightly repayments can save money because you make more payments per year. Fortnightly payments are equivalent to 13 monthly payments per year instead of 12, helping you pay off your loan faster.

What is a comparison rate?

The comparison rate includes both the interest rate and most fees and charges, giving you a more accurate picture of the true cost of a loan. Always compare loans using the comparison rate rather than just the headline rate.

What is an offset account?

An offset account is a transaction account linked to your mortgage. The balance offsets your loan balance for interest calculations. For example, $50,000 in offset against a $500,000 loan means you only pay interest on $450,000.

Should I fix my interest rate?

Fixed rates provide certainty — your repayments won't change during the fixed period. However, you may miss out if rates drop, and there are often restrictions on extra repayments. Many borrowers split their loan between fixed and variable.

Tax Accuracy & Sources

Reviewed: March 2026 · Tax year: 2025-26

Estimates mortgage repayments and interest using the standard PMT formula. Does not account for lender fees, comparison rates, lenders mortgage insurance, offset account interest calculations, or redraw facilities.