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Bigger Down Payment vs Smaller Down Payment: How Much Can You Really Save?

If you put another $25,000 down on a home, does it actually make much difference? Compared with the price of a property, $25,000 may not sound enormous. But every dollar you don't borrow is a dollar you don't pay interest on — potentially for decades. A larger down payment can lower your regular repayment, reduce the interest paid over the life of the loan and, in some cases, affect other borrowing costs such as mortgage insurance.

Below, we compare two buyers purchasing the same property with different down payments, then look at when putting more down can be worth it — and when keeping the cash may make more sense. In Australia, a down payment is usually called a deposit; the two terms are used interchangeably here.

An Example: $75,000 Down vs $100,000 Down

Consider an illustrative $500,000 property. Both scenarios use the same 6.5% annual interest rate, a 30-year term and standard monthly principal-and-interest repayments, so the only difference is the size of the down payment.

• Scenario A — $75,000 down (15%), borrowing $425,000
• Scenario B — $100,000 down (20%), borrowing $400,000

All figures are illustrative estimates based on a 6.5% fixed rate for the full 30-year term, monthly repayments and no fees, mortgage insurance, taxes or rate changes. Total amount repaid includes the loan principal but not the down payment.

In plain English: Scenario B borrows $25,000 less, so each month there is less principal for interest to be charged on. That lowers the repayment needed to clear the loan within 30 years, and because the smaller balance carries through every month of the loan, the interest saving builds up to roughly $31,900 over the full term. The total amount repaid falls by about $56,900 — the $25,000 not borrowed plus the interest that would have been charged on it.

1. Why a Bigger Down Payment Can Make a Difference

Mortgage interest is generally calculated on the outstanding loan balance. Borrow less, and the balance interest is charged on is smaller from the very first repayment. In the example, the first month's interest is about $2,302 in Scenario A and about $2,167 in Scenario B — a difference of around $135 in month one alone.

That gap doesn't disappear after the first month. Because the lower balance carries forward, future interest charges are calculated on a smaller outstanding amount. Over a long mortgage term, those individual interest reductions can add up to a substantial cumulative saving. For a closer look at the maths behind this, see how mortgage repayments are calculated.

2. The Monthly Repayment Difference

In the example, the extra $25,000 down reduces the estimated monthly repayment by about $158, from $2,686 to $2,528. On its own, $158 a month may not look dramatic. In context:

• It adds up to roughly $1,900 a year in lower repayments.
• It is a reduction of nearly 6% in the regular repayment — in line with borrowing about 6% less.
• It applies every month for the life of the loan, assuming rates and terms stay the same.

For some households, a lower repayment can make the budget noticeably more comfortable, particularly in the early years of owning a home when other costs tend to be high. For others, $158 a month may matter less than having $25,000 available in cash.

3. The Long-Term Interest Difference

The more important difference is often the cumulative interest. Over 30 years, the estimated interest falls from about $542,064 to about $510,177 — a saving of roughly $31,887, which is more than the extra $25,000 put down.

This is the same principle that makes early extra repayments effective: reducing principal sooner means less interest accrues over every remaining month. If the rate is higher, or the loan runs for the full term, the long-term difference tends to be larger; if the loan is repaid early or refinanced, the actual saving may be smaller. Our guide to how extra repayments can reduce mortgage interest explores this effect in more detail.

4. Mortgage Insurance Can Change the Equation

Down-payment size can affect more than the loan amount. In the example, Scenario A borrows 85% of the property value while Scenario B borrows 80% — and the loan-to-value ratio (LVR, or LTV in the US) is often used by lenders when deciding whether mortgage insurance applies.

• United States: conventional mortgages with less than 20% down may involve private mortgage insurance (PMI), depending on the loan. PMI is typically an added monthly cost, and on many conventional loans it can be removed once enough equity is built, subject to lender and loan rules. Government-backed loans such as FHA loans have their own separate mortgage insurance requirements.
• Australia: a higher loan-to-value ratio — commonly above 80% — may result in Lenders Mortgage Insurance (LMI), depending on the lender and your circumstances. LMI is often a one-off premium that may be paid upfront or added to the loan. Some borrowers may qualify for waivers or government schemes.

Mortgage insurance does not always apply, and thresholds, costs and exemptions vary by lender, loan type and country. Where it does apply, the potential insurance saving can sometimes outweigh the repayment and interest differences shown above. Learn more in Lenders Mortgage Insurance Explained.

5. But Putting More Down Isn't Automatically Better

Mathematically, borrowing less usually means paying less interest. But the lowest possible mortgage balance is not necessarily the best financial decision for every borrower. Money put into a down payment is generally tied up in the property and can be harder to access later. Before committing an extra $25,000, it can help to consider:

• Emergency fund — whether you would still have enough savings to cover job loss, illness or unexpected bills.
• Moving costs — removalists, furniture, utilities connections and other upfront expenses.
• Closing and purchase costs — such as closing costs in the US or stamp duty and legal fees in Australia, which usually need to be paid in cash.
• Repairs and renovations — homes, especially older ones, can need work soon after purchase.
• Other debts — higher-interest debt such as credit cards or personal loans may cost more than the mortgage.
• Investing — depending on your goals, timeframe and risk tolerance, some people choose to invest cash elsewhere rather than reduce their mortgage. Returns are not guaranteed.
• Cash reserves — some lenders look at savings remaining after purchase, and having a buffer can make it easier to handle rate rises or changes in income.

In some markets, loan features such as an offset account may let you reduce interest while keeping funds accessible — see Offset Account vs Redraw Facility. Availability varies by lender and country.

6. When a Bigger Down Payment May Be More Valuable

The value of a larger down payment isn't the same for everyone. It may have a particularly meaningful effect when it:

• Crosses an important loan-to-value threshold — for example moving from above 80% LVR to 80% or below, which can change how lenders assess the loan.
• Potentially reduces or avoids mortgage insurance — where PMI or LMI would otherwise apply, though this is not guaranteed.
• Makes repayments more manageable — a lower repayment may provide more room in the household budget.
• Improves borrowing affordability — a smaller loan relative to income may sit more comfortably within a lender’s assessment, although approval depends on many factors.
• Reduces total interest exposure — particularly at higher interest rates or over longer loan terms.

Our Mortgage Deposit Guide covers deposit sizes and loan-to-value ratios in more depth. This article is general information only and doesn't take your personal circumstances into account.

7. $25,000 Down vs $25,000 Paid Later

It might seem that putting $25,000 down at purchase and paying an extra $25,000 off the mortgage a few years later would end up in the same place. They are not necessarily financially identical.

When the $25,000 goes into the down payment, the mortgage starts with a lower principal balance. If you instead borrow the additional $25,000 and make a lump-sum repayment later, interest will have been charged on the higher outstanding balance in the meantime. The longer the principal remains higher, the more opportunity there is for additional interest to accumulate.

That said, the comparison isn't always one-sided. Keeping the cash initially provides flexibility, and a later lump sum can still meaningfully reduce interest and shorten the loan. Mortgage structure, timing, mortgage insurance, fees, break costs and lender rules on extra repayments can all affect the result. You can model lump-sum and regular extra repayments in the calculator, or read how to pay off your mortgage earlier.

Frequently Asked Questions

Conclusion

An extra $25,000 down won't transform every mortgage, but it isn't trivial either. In this example, increasing the down payment from $75,000 to $100,000 reduces the estimated monthly principal-and-interest repayment by about $158 and reduces estimated interest over 30 years by approximately $31,887.

But that doesn't automatically mean putting the extra $25,000 into the property is the better financial decision. Keeping more cash available can provide flexibility for emergencies, purchase costs, repairs, other debts or investments. And if a larger down payment moves the loan across an important loan-to-value threshold, the effect on mortgage insurance may also need to be considered.

The right balance depends on the loan and the borrower's circumstances. Running different down-payment amounts through the Smarter Mortgage Calculator can help show how the numbers change.