Estimate the family guarantee needed to buy with little or no deposit and avoid Lenders Mortgage Insurance — and see why the structure of the guarantee matters more than the headline figure.
What a guarantor calculator estimates
A family guarantee lets you buy with little or no deposit by adding a guarantor's property equity as extra security. The lender then holds enough combined security to bring your loan to 80 per cent of value — the threshold below which Lenders Mortgage Insurance is usually waived. The calculator above estimates the size of that guarantee from your purchase price, costs and whatever deposit you contribute, and shows the loan you would need to support.
What drives the number
Two figures do the work: your loan-to-value ratio against your own property, and the security shortfall a guarantee has to close. With no deposit, your loan sits above 80 per cent on your property alone, so the guarantee covers the gap between your property's value and the total security the lender wants. The larger your own contribution, the smaller the guarantee. Most lenders accept a limited guarantee — capped to the shortfall, not the guarantor's whole home — and release it once the loan is paid down enough that your property stands on its own. Policy varies on who can act as guarantor, how much equity they need, and the cap they will accept, which is the real question behind any guarantee.
Use it as a starting point
Treat the result as a way to frame the conversation, not a commitment. A guarantee changes the position of two families at once, so it pays to structure it deliberately and to have the guarantor take independent legal advice. Book a strategy session and we will work through which lender's guarantee policy fits your circumstances.
General information only — not personal financial product or credit advice. The estimate is indicative and depends on each lender's policy, current rates and your full circumstances. AeFin is an Australian Credit Representative (CR 464548) of Finsure (ACL 384704).