The Finance Algorithm

Guarantor Loan Calculator

Calculate the benefits and risks of having a guarantor on your personal loan

Updated October 2026Built and checked by MaverickHow it's calculatedReport an error

Your numbers

Updates as you type
$
$20k

How much do you need to borrow?

5

How long to repay the loan

%
15%

Rate you'd get on your own (or if you can't get approved)

%
9%

Better rate available with a guarantor

Lenders' likely response to your application alone

Most lenders require a close family member

The button asks our AI to explain these figures in words.

Guarantor loan: cost and exposure

Monthly difference

$61

lower with a guarantor

Interest difference

$3,638

over 5 years

Rate gap

6.00%

between the two quotes

Guarantor exposure

$20,000

the loan plus interest, unless the guarantee is limited

With vs without a guarantor

Same loan, same term: only the rate differs.

$476Without (15%)$415With (9%)

Lifetime cost of the loan

Principal plus the interest at each rate over the full term.

$28,548Without (15%)$24,910With (9%)

What you pay back

The principal is the same in both: only the interest differs.

$28,548Without guarantor$24,910With guarantor
What the guarantor takes on
A 6.00% lower rate saves $3,638 in interest
If you can't repay, your parent may have to repay the whole loan plus interest, and the lender can take any asset they put up as security. A limited guarantee caps the amount. Moneysmart suggests getting independent legal or financial advice before signing, and notes it can be hard to get out of a guarantee once the borrower can't repay.

How it works

A guarantor can get you approved, or onto a better rate, by putting their own property or income behind your loan. This shows what that could save you, and what your guarantor would be on the hook for if you couldn't pay.

  1. 1Enter the loan amount you need
  2. 2Set your preferred loan term
  3. 3Add the rate you'd get without a guarantor
  4. 4Enter the better rate available with a guarantor
  5. 5Select your current approval status and guarantor relationship

The figures today

As of 7 November 2026, the lowest personal loan rate is 5.80%, from Plenti Personal Loan, while the typical best across 68 institutions is 7.96%.

Personal loan rates

Worked examples

Recent Graduate

Emma has no credit history and would be declined alone. With her mum as guarantor she's offered $10,000 at 9% over 5 years, against 15% if she could get approved.

Loan amount
$10,000
Loan term (years)
5
Rate without guarantor
15%
Rate with guarantor
9%
Your approval status
Would be declined without guarantor
Guarantor relationship
Parent

The guarantee gets the loan approved, at $208 a month and $2,455 of interest - $1,819 less than at 15%. Her mum is liable for up to the full $10,000 if Emma doesn't pay.

Credit Recovery

Mike is borderline for approval. With his sister as guarantor he's offered $15,000 at 10% over 5 years, against 16% alone.

Loan amount
$15,000
Loan term (years)
5
Rate without guarantor
16%
Rate with guarantor
10%
Your approval status
Borderline - may be declined
Guarantor relationship
Sibling

The guaranteed loan costs $319 a month and $4,122 of interest, $2,764 less than at 16%. His sister takes on up to $15,000 of risk, so both should get independent advice.

Questions people ask

What are the risks for a guarantor?
The guarantor is legally responsible for the full loan amount if you default. Their credit score is affected, and they may be sued or have assets seized. They should only guarantee if they can afford to repay the entire loan.
Can I remove a guarantor later?
Some lenders will release a guarantor once the loan is paid down or the borrower qualifies alone. Ask before signing, and get the conditions in writing.
Who can be a guarantor?
Most lenders require guarantors to be close family members (parents, siblings, sometimes grandparents), Australian residents, and have a good credit history and stable income.
Does being a guarantor affect credit score?
Yes. The guaranteed loan appears on the guarantor's credit report and counts towards their borrowing capacity. If payments are missed, it damages their credit too.

The terms, in plain English

Guarantor
A person who legally agrees to repay your loan if you fail to do so.
Guarantee Release
Removing the guarantor from the loan after proving your ability to repay independently.
Joint Liability
The guarantor is equally responsible for the debt and can be pursued for the full amount.
Credit Impact
The loan appears on both the borrower's and guarantor's credit reports.

Official sources

Secured vs Unsecured

Another way to get better rates without a guarantor

Personal Loan Calculator

Calculate repayments with your guarantor rate