Paying an Extra $200 a Month on Your Mortgage — How Much Do You Save?

Exact interest savings and years saved for common Australian loan sizes at current rates.

An extra $200 a month on your mortgage might not feel like much — but over a 30-year loan it can save you more than $100,000 in interest and take close to four years off your loan term. Here is exactly how the numbers work, and how to calculate the saving for your specific loan.

How Much Does an Extra $200/Month Save? — By Loan Size and Rate

The figures below are for a 30-year loan with extra repayments starting from the beginning.

30-year term. Extra $200/month from month one. Figures calculated using standard monthly amortisation. Actual savings vary based on your lender's interest calculation method and when repayments start.

Why a Higher Interest Rate Means Bigger Savings

You might notice that on the same loan amount, a higher interest rate produces a larger interest saving from the same $200/month extra. This is not a mistake — it is how compound interest works.

When your rate is higher, every dollar of principal you eliminate is carrying a heavier interest burden. Reducing the balance by $200 at 6.5% saves more interest per month than reducing it by $200 at 5.5%, and that difference compounds over years. Put simply: the more expensive your loan, the more powerful extra repayments become.

Why a Smaller Loan Saves More Years (But Less Dollars)

You will also notice that a $400,000 loan saves more years than an $800,000 loan for the same $200/month extra — even though the dollar saving is lower. This is because $200/month is a larger proportion of the minimum repayment on a smaller loan, so it pays down the principal faster relative to the loan size.

On a large loan, $200/month makes a smaller dent proportionally — it still saves a significant amount of interest in dollar terms, but the loan term reduces by less.

Where Does $200 a Month Come From?

For most households, an extra $200 a month does not require a dramatic lifestyle change. Common sources:

• Salary review or pay rise: Rather than increasing spending to match a pay increase, redirect part of it straight to the mortgage.
• Switching to fortnightly repayments: Many lenders let you pay half your monthly repayment every two weeks. Because there are 26 fortnights in a year (not 24), this is equivalent to making an extra monthly payment each year — often around $150–$250 depending on your loan size.
• Rounding up repayments: If your minimum monthly repayment is $3,650, rounding up to $3,850 adds $200 extra with minimal planning effort.
• Tax refunds split monthly: The average Australian tax refund is around $2,400. Spread over 12 months, that is $200/month.

What if You Start Later?

The table above assumes extra repayments start from month one. Starting later still saves a meaningful amount — but the saving is smaller, because the balance you are reducing has already accrued several years of interest.

As a rough guide: starting $200/month extra at year five rather than year one reduces your interest saving by roughly 20–25% on a typical Australian loan. The earlier you start, the better — but starting late is still far better than not starting at all.

Use the Mortgage Paydown Calculator to model your exact scenario — enter your current loan details, set the extra repayment start date to today, and see your precise saving.