Getting the Most From a Loan Comparison Calculator: Tips and Common Errors

Updated 1 August 2026 · Loans and credit

A Loan Comparison Calculator gives a fast answer, but the answer is only as good as what goes in. These are the mistakes we see most often with loan comparison calculations in Australia, and how to avoid them.

1. Focusing on the monthly repayment

A longer term lowers repayments but raises total interest. Look at the total cost.

2. Paying only the minimum

Minimum repayments on credit cards can take decades and cost more than the original balance.

3. Ignoring fees

Establishment, monthly and early repayment fees can outweigh a lower interest rate.

4. Not planning for a balloon payment

A balloon lowers repayments now but leaves a large lump sum to pay or refinance later.

5. Overlooking the detail that matters most here

On small or short loans, fees often matter more than a small difference in rate.

How the cheaper option changes with loan term

A common mistake is getting one input slightly wrong. Here is what happens to the cheaper option when “Loan term (years)” is off by up to 20% in either direction, with everything else held steady.

Loan term (years)	Cheaper option
4	Loan A by $366.94
5	Loan A by $276.91
6	Loan A by $183.59

At 4 the result is Loan A by $366.94; at 6 it is Loan A by $183.59. If a small change in this input moves the answer a lot, it is worth double-checking that figure before you rely on the result.

A quick sense check

Total cost = monthly repayment × months + fees for each loan. With typical inputs the calculator returns cheaper option of Loan A by $276.91. If your own result looks wildly different, check that each figure is in the right unit and period (weekly, monthly or yearly) before drawing conclusions.