Guarantor Home Loan Calculator

Use our guarantor home loan calculator to estimate how much additional property security your guarantor may need to provide and whether they appear to have enough usable equity.

The calculator is designed to answer a specific question: is there enough guarantor equity to support the proposed loan?

It does not calculate how much you can afford to borrow or confirm that you qualify for a guarantor home loan.

How does this calculator work?

The Guarantor Loan Calculator is a precise, user-friendly tool designed to estimate the limited guarantee size required for your home loan application when using a guarantor, as well as provide insight into potential approval challenges with lenders. By entering specific details into the calculator such as the value of the property you plan to purchase, the amount you intend to borrow, the value of your guarantor’s property, and any outstanding loan amount on their property, you’ll receive an immediate result that reflects your borrowing potential.

Unlike standard home loans, policies for guarantor loans can vary from one bank to another. As a result, it’s essential to understand how each lender will view your application. Applying with the right lender the first time around prevents you from damaging your credit score by having too many unnecessary enquiries on your credit file.

For more information, visit our page on guarantor home loans. It covers loan types, strategies for managing the size of your guarantee, and how you can potentially borrow above 100% of the property’s value.

How Much Equity Does A Guarantor Need?

There is no fixed dollar amount that every guarantor needs.

The amount depends on:

• The property price
• Your proposed loan
• Your own contribution
• The guarantor property value
• Debt already secured against that property
• The lender’s valuation
• The lender’s guarantor policy

As a simple guide, this calculator uses:

Guarantor property value × 80% − Existing debt

For example, if the property is worth $800,000 and the guarantor owes $300,000:

$800,000 × 80% − $300,000 = $340,000 estimated usable equity

If the required guarantee is $150,000, the equity appears sufficient under the calculator assumptions.

However, the lender’s valuation matters. A lower valuation reduces the usable equity available even though the guarantor’s actual mortgage balance has not changed.

What Does A Limited Guarantee Mean?

A limited guarantee restricts the guarantor’s guarantee to an agreed amount instead of automatically guaranteeing the borrower’s entire home loan.

For example, the loan might be $600,000 but the agreed limited guarantee only $150,000.

The guarantee documents determine the guarantor’s actual obligations. Depending on the contract, the guarantor’s exposure may also include amounts such as interest, fees or recovery costs associated with the guaranteed debt.

A limited guarantee can reduce unnecessary exposure compared with guaranteeing the entire loan, but it does not make acting as guarantor risk-free.

Independent legal advice is important so the guarantor understands exactly what they are agreeing to.

Can My Guarantor Still Have A Mortgage?

Yes, your guarantor can still have a mortgage.

Your guarantor does not necessarily need to own their property outright. However, the existing mortgage reduces the amount of equity that may be available.

There is also a second question the calculator cannot answer:

Who already holds the mortgage over the guarantor’s property?

Depending on the lenders involved, the proposed arrangement may require a second mortgage, consent from an existing lender, or a different loan structure.

This is why two guarantors with the same property value and the same amount of equity can still have different lending options.

If your guarantor already has a home loan, it is worth checking the structure before relying on the calculator result.