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Calculator guide

Updated 2026-08-23

How to Compare Loan Payments

Two loans can have a similar monthly payment and very different total costs. This guide explains the numbers behind a loan estimate so you can compare offers using the same assumptions.

Open the loan calculator

Start with matching inputs

Enter the same amount borrowed, annual interest rate and repayment period for each scenario. If one offer uses a different term, fee, payment frequency or variable rate, it is not a like-for-like comparison.

The calculator estimates a regular amortising payment. It separates the expected monthly payment, total repayment and total interest so that a lower monthly number is not mistaken for a lower overall cost.

What changes the result

  • A higher interest rate increases the interest portion of the payment.
  • A longer term usually reduces the monthly payment but increases the number of interest-bearing payments.
  • A larger deposit or smaller principal reduces the amount on which interest is calculated.
  • Fees, insurance and variable-rate changes can make the lender’s actual cost different from a simple estimate.

A simple comparison method

  1. Calculate the offer using the quoted principal, rate and term.
  2. Record the monthly payment and total repayment.
  3. Add any known upfront or recurring fees separately.
  4. Ask the lender which assumptions can change before you decide.

Use the result carefully

This is a planning tool, not a credit decision or a loan offer. For an important borrowing decision, use the lender’s formal disclosure and check the currency, rate type, fees and early settlement terms.

Common questions

Should I compare monthly payment or total repayment?

Both. The monthly payment helps with cash-flow planning, while total repayment shows the long-term cost under the entered assumptions.

Does the calculator include lender fees?

No. Add fees separately or compare them using the lender’s formal quotation.

Can a longer loan cost more overall?

Yes. Spreading payments over a longer period can lower the monthly amount while increasing total interest.