On a $500,000 mortgage at 5.5%, you will pay roughly $522,000 in interest over 30 years. That is more than the house cost. But throw an extra $200 a month at it and you save $89,000 in interest and finish nearly 5 years early. The maths on extra repayments is hard to argue with.
Below are the actual numbers for different extra repayment amounts, how the mechanics work, and practical ways to find that extra cash without upending your life.
How Extra Repayments Work
When you make your regular mortgage repayment, a portion goes toward the interest charged on your outstanding balance, and the rest chips away at the principal (the actual amount you owe). Early in your loan, the lion's share of each payment goes to interest, with only a small sliver reducing your principal. This is the nature of amortisation.
Extra repayments change this equation in your favour. Any additional money you pay goes directly toward reducing your principal balance. A smaller principal means less interest is charged in the next period, which means more of your regular repayment goes toward principal, which means even less interest the following period, and so on. It is compound interest working in reverse — and in your favour for once.
The Real Numbers: $500,000 Loan at 5.5%
Let us look at a concrete example. Say you have a $500,000 home loan at 5.5% interest over 30 years with monthly repayments.
Without Extra Repayments
- Monthly repayment: approximately $2,839
- Total interest over 30 years: approximately $522,000
- Total amount paid: approximately $1,022,000
You read that correctly — you would pay more than double the original loan amount over the full term.
With an Extra $200 Per Month
- Monthly repayment: $2,839 + $200 = $3,039
- Total interest saved: approximately $89,000
- Time saved: approximately 4 years and 8 months
- New loan term: roughly 25 years and 4 months
With an Extra $500 Per Month
- Monthly repayment: $2,839 + $500 = $3,339
- Total interest saved: approximately $172,000
- Time saved: approximately 9 years
- New loan term: roughly 21 years
Half a million dollars in interest drops to $350,000, and you are mortgage-free almost a decade sooner. Want to see how your own numbers stack up? Try our mortgage extra repayment calculator to run the figures for your specific loan.
With an Extra $1,000 Per Month
- Total interest saved: approximately $255,000
- Time saved: approximately 13 years
- New loan term: roughly 17 years
The pattern is clear: the more you pay, the faster the snowball effect kicks in. But even small amounts make a genuine difference.
Why Early Extra Repayments Matter Most
The impact of extra repayments is not linear. An extra $200 per month in the first year of your loan saves far more than the same $200 in year 20. This is because of how compound interest works.
In the early years of a 30-year mortgage, roughly 70% of each repayment goes to interest and only 30% to principal. Any extra payment you make during this period has decades of compounding benefit ahead of it. Every dollar of principal you eliminate in year one would have generated interest for the next 29 years.
By contrast, in the final years of your loan, most of your repayment already goes to principal, and there is less time for the savings to compound. Extra repayments still help, but the effect is significantly smaller.
Offset Accounts vs Redraw Facilities
There are two main ways to park extra funds against your mortgage without locking them away permanently: offset accounts and redraw facilities. Both reduce the interest you pay, but they work differently and have distinct pros and cons.
Offset Account
An offset account is a transaction or savings account linked to your home loan. The balance in this account is "offset" against your mortgage principal when interest is calculated. For example, if you owe $500,000 and have $30,000 in your offset account, you only pay interest on $470,000.
- Pro: Your money stays fully accessible at all times
- Pro: Works like a regular bank account for everyday spending
- Pro: No tax on the "interest saved" (unlike a savings account)
- Con: Loans with offset accounts sometimes have higher interest rates or monthly fees
For a deeper look, read our full guide on how offset accounts work and when they are worth it.
Redraw Facility
A redraw facility lets you make extra repayments directly into your loan, then withdraw (redraw) those funds later if you need them. The extra money reduces your balance and the interest you are charged.
- Pro: Often available on basic variable loans with no extra fees
- Pro: Directly reduces your principal balance
- Con: Some lenders restrict redraw amounts or charge fees to redraw
- Con: Redraw funds may not be available instantly
- Con: Your lender could technically change redraw terms
Which Should You Choose?
If you value flexibility and use your extra funds as an everyday transaction buffer, an offset account is usually the better choice. If you want to make lump sum extra repayments and are unlikely to need the money back soon, a redraw facility on a basic loan can save you on fees. Many borrowers use both: an offset for daily cash flow and redraw for larger windfalls.
Potential Restrictions to Watch For
Before you start making extra repayments, check your loan terms carefully. Not all home loans treat extra repayments the same way.
Fixed Rate Loan Limits
If you have a fixed rate mortgage, there are almost always caps on how much you can pay extra. Most Australian lenders allow between $5,000 and $30,000 in additional repayments per year on a fixed loan. Go over that limit, and you could face break costs -- penalty fees that can run into thousands of dollars.
If you are on a fixed rate and want to make significant extra repayments, consider whether a variable rate or split loan might suit you better.
Early Repayment Fees
Some older loan products, or certain fixed rate loans, charge early repayment fees (also called early exit fees or discharge fees). While these have been banned on new loans since 2011 in Australia, if you have an older loan, it is worth checking. The fee structure could erode some of the benefit of your extra repayments.
Redraw Restrictions
If you are relying on being able to redraw your extra payments, make sure you understand your lender's specific terms. Some charge a fee per redraw, some have minimum redraw amounts, and some require you to maintain a buffer above your minimum repayment schedule.
10 Practical Tips for Making Extra Repayments
Here are ten practical ways to find extra repayment money:
- Set up automatic extra payments. Even $50 per week adds up to $2,600 per year. Automating your finances removes the temptation to spend the money elsewhere.
- Round up your repayments. If your minimum is $2,839, round up to $3,000. You barely notice the difference, but it adds up significantly over time.
- Switch to fortnightly payments. By paying half your monthly repayment every two weeks, you end up making 26 half-payments per year instead of 12 full payments -- that is the equivalent of 13 monthly payments instead of 12.
- Put windfalls straight onto the mortgage. Tax refunds, work bonuses, birthday money, and inheritance -- directing lump sums to your home loan has an outsized impact.
- Use your offset account as your main transaction account. Every dollar sitting in your offset, even temporarily, reduces the interest you are charged.
- Review your budget with the 50/30/20 rule. If you can trim your "wants" spending by even 5%, that freed-up cash can go straight to your mortgage.
- Direct pay rises to your mortgage. If you get a raise, keep living on your old salary and put the difference toward extra repayments. You will not miss money you never had in your budget.
- Refinance to a lower rate but keep paying the same amount. If you refinance to a lower rate, do not reduce your repayments. Keep paying the same dollar amount and the difference goes straight to principal.
- Cancel unnecessary subscriptions. That $15 streaming service you never watch? Over 25 years on your mortgage, redirecting it could save you thousands in interest.
- Tackle it as a team. If you have a partner, agree on an extra repayment goal together. Shared motivation makes it far easier to stick with it.
Extra Repayments vs Other Financial Goals
Should you throw every spare dollar at your mortgage? Not necessarily. Financial wellbeing is about balance. Before aggressively paying down your home loan, consider whether you have:
- An emergency fund: Most experts recommend 3 to 6 months of expenses set aside before making extra mortgage payments. Without a safety net, an unexpected expense could force you into high-interest debt. See our guide on building an emergency fund from scratch.
- High-interest debt: If you have credit card debt at 20% interest, paying that off first will save you more per dollar than putting extra on a 5.5% mortgage.
- Adequate superannuation: Make sure you are on track for retirement. In some cases, salary sacrificing into super can be more tax-effective than extra mortgage repayments.
Once those bases are covered, directing surplus cash to your mortgage is one of the most reliable financial moves you can make. It is a guaranteed, risk-free return equal to your mortgage interest rate.
A Quick Comparison: Extra Repayments on a $500K Loan at 5.5%
| Extra Per Month | Interest Saved | Years Saved | New Loan Term |
|---|---|---|---|
| $0 | $0 | 0 | 30 years |
| $100 | ~$50,000 | ~2.5 | ~27.5 years |
| $200 | ~$89,000 | ~4.7 | ~25.3 years |
| $500 | ~$172,000 | ~9 | ~21 years |
| $1,000 | ~$255,000 | ~13 | ~17 years |
The Short Version
Pay more than the minimum, as consistently as you can. That is genuinely it. No complex strategy required.
Quick summary:
- Even small extra payments ($50-$200 per month) save tens of thousands of dollars in interest
- The earlier you start, the bigger the impact due to compound interest working in your favour
- Use an offset account or redraw facility to maintain flexibility
- Check your loan terms for any extra repayment restrictions, especially on fixed rate loans
- Balance extra repayments with building an emergency fund and paying off high-interest debt first
Plug your own loan details into our mortgage extra repayment calculator and see the specific numbers. Even $50 a week makes a measurable dent.