Renovation finance calculator
A top-up is cheaper on the rate; a personal loan is cheaper on the term. Enter the renovation cost, your home loan rate and a personal loan rate, and see the monthly repayment and total interest of the three ways to fund it.
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.
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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.
At the defaults, $100,000 at 6% over 25 years is about $93,290 of interest, about $37,290 on a 7-year personal loan at 9.5%, and about $33,230 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. At this calculator's defaults, $100,000 at 6% over 25 years costs about $93,290 in interest, the same amount on a 7-year personal loan at 9.5% about $37,290, and the top-up cleared in 10 years about $33,230. 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, on 10 October 2026 CommBank, Westpac and NAB published unsecured ranges from 6.99% to 22.25% p.a. (comparison 8.40% to 23.53%), Westpac a 16.99% median, and NAB 7.50% to 12.99% (8.54% to 13.96% comparison) for its home loan customers. The 6% and 9.5% defaults are examples.
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. On a personal loan add the upfront fee ($250 at CommBank and Westpac, none at Pepper Money, waived at Great Southern Bank to 23 February 2027) and any monthly fee ($15 at CommBank, Westpac and NAB), as published on 10 October 2026. On the home loan side add any valuation or 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), as published on 10 October 2026. Equity borrowing is limited by usable equity, usually 80% of the property value minus the loan balance; the home equity calculator works it out. Structural work usually needs a construction loan.
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.