Calculator

The only number that settles it

A lower rate is not a saving until it has paid for the move. Total switching cost, minus any cashback, divided by the monthly saving, gives the month you break even. If you expect to sell, move or refinance again before that month, the saving never arrives.

Loan balance$ Remaining termyrs Current rate% New rate% Discharge fee$ New lender fees$ Government registration$ Fixed break cost$ Cashback offered$

Current repayment: —
New repayment: —
Monthly saving: —
Net cost to move: —
Break-even month: —
Saved over the remaining term: —

What this assumes

Both loans are principal and interest over the same remaining term, at a rate that does not change.
The new rate is held constant. It will not be — which is why the break-even month matters more than the total.
Government registration covers both discharging the old mortgage and registering the new one; the amounts differ by state and are published by the land registries.
A cashback is treated as a straight reduction in the cost of moving. It is not, if a clawback clause requires you to keep the loan for a minimum period — check that period against the break-even month.
Excludes lenders mortgage insurance, which applies again if the new loan is above 80% of value and does not transfer between lenders.

An estimate for comparing two scenarios under identical assumptions, not a quote or an approval. Rate data on this site is as at 2026-08-04; confirm any figure on the lender's own terms page.

Before you use the number

Ask your current lender to match first. A repricing request is free, takes days, and needs no application. Whatever they offer becomes the rate the switch has to beat — not the rate you are paying today.
Get the break cost in writing. If any part of the loan is fixed, this is calculated at the time and can dwarf every other line here.
Check the clawback period. A cashback that must be repaid if you leave within two years is a lock-in with a payment attached.
Keep the remaining term. Resetting to 30 years lowers the repayment and raises the total. If you want the cash flow, choose it deliberately.

General information only, not financial advice. Published by the team behind Arrivau, an Australian finance business.