Renovation finance calculator
Your renovation and rates
Interest only; fees, valuation and LMI are excluded. Personal loans cap out between $50,000 and $75,000 depending on the lender, so amounts above that are equity or construction loan territory.
The three routes on $100,000
The top-up rows assume the extra borrowing is priced at your home loan rate. The faster-repayment row is the one to compare with the personal loan: same discipline, lower rate.
Want the routes priced on your actual loan?
A licensed broker partner can confirm your usable equity, your lender's top-up minimum and rate, whether a supplementary loan or refinance beats it if you are fixed, and a personalised personal loan rate for comparison.
How the renovation finance calculator works
Each row is a standard principal-and-interest amortisation of the renovation amount at the rate and term you enter. The first row is what most owners do by default: add the cost to the mortgage and let it run for the remaining term. The second row is the same borrowing at the same rate but repaid over a short term, which is what a split or supplementary loan does, or what you achieve by making extra repayments on the top-up; the extra repayment calculator shows the effect on the whole loan. The third row is a personal loan over one to seven years at an unsecured rate.
The defaults reproduce the example Emu Money publishes: $100,000 at 6% over 25 years is $93,290 of interest, $36,680 on a 7-year personal loan at 9.5%, and $33,220 on the top-up cleared in 10 years. The lesson is that the term decides the outcome more than the rate, so a top-up is the cheapest route only when you commit to clearing it. The renovation loans guide covers which route fits which project and what each lender publishes; the renovation personal loans guide has the caps, rate ranges and fees by lender.
Related guides and calculators
Renovation finance calculator FAQs
Is a top-up cheaper than a personal loan for a renovation?
On the rate, always; on the total interest, only if you repay it faster than the mortgage. Emu Money publishes the example this calculator reproduces: $100,000 at 6% over 25 years costs $93,290 in interest, the same amount on a 7-year personal loan at 9.5% costs $36,680, and the top-up cleared in 10 years costs $33,220. Set the accelerated term to the personal loan term and compare the two rows directly.
What rates should I enter?
Your current home loan rate for the top-up rows, since a top-up is usually priced at the same rate as the loan it joins, and a personalised personal loan rate if you have a quote. Without one, the published ranges run from about 7.25% to 22.75% at the big four, and Westpac publishes a median of 16.99%; NAB publishes 7.50% to 12.99% for its home loan customers. The calculator defaults to 6% and 9.5% to match the Emu Money example.
How much would a $50,000 home equity loan cost per month?
At 6%, about $322 a month over 25 years, $555 over 10 years or $731 over 7 years. The same $50,000 as a 7-year personal loan at 9.5% is about $817 a month. Enter $50,000 above to see the total interest on each.
Does the calculator include fees?
No, it compares interest only. Add a personal loan establishment fee ($250 at CommBank, waived until 9 October 2026; none at Pepper Money or Great Southern Bank) and NAB’s $15 monthly fee, or on the home loan side a valuation of $300 to $600, any top-up fee, and lenders mortgage insurance if the new total passes 80% of the property value.
How much can I borrow for a renovation loan?
Personal loans cap out at $50,000 (CommBank), $55,000 (NAB), $60,000 (ING), $70,000 (Westpac) or $75,000 (ANZ, Plenti, Great Southern Bank). Equity borrowing is limited by usable equity, which is 80% of the property value minus the loan balance; the home equity calculator works it out. Westpac treats renovations over $250,000 as construction loans.
Does using this calculator affect my credit score?
No. It runs in your browser on the numbers you type and nothing is lodged or checked. A credit enquiry happens only when you apply with a lender.