Mortgage break fee calculator
You've seen a lower rate advertised, or your bank has offered you one. The question is whether breaking your current fixed term is worth what it costs to get out.
This calculator answers that.
Enter your details in the purple cells. Yours to keep and change.
First: this doesn't calculate your break fee
Worth being upfront, because it's what most people arrive looking for.
Every bank calculates break costs differently, using their own funding rates and their own formula. There's no reliable way to work it out from the outside, and any calculator claiming to do so is guessing.
Ring your bank and ask what it would cost to break your fixed term. They'll give you a figure, usually valid for a short window. That takes five minutes and it's the only number that counts.
Then come back here with it. This calculator does the part the bank won't do for you — tells you whether paying that fee actually leaves you better off.
What you'll need
Your current home loan rate
The rate you'd move to
The size of your loan
Your break fee, from the bank
Months remaining on your current fixed term
Out the other side: what you'd save, if anything, by breaking now.
The trap in "savings"
This is the part worth reading before you act on any number the calculator gives you.
Breaking to a lower rate can look like an obvious win. But breaking also means fixing again — and you're locking in today's rate for a new term, starting now.
If rates keep falling, the rate you've just locked could turn out to be higher than what you could have had by simply waiting until your current term ended. Your "saving" then isn't a saving at all. You've paid a fee to lock in a rate you'd have beaten anyway.
So the real question isn't only "is the new rate lower than my current one". It's:
Is it lower than what I'd expect to be able to fix at when my term ends naturally?
How many months am I actually buying? Breaking with two months left rarely stacks up.
Am I comfortable being locked in from today rather than from my current end date?
Nobody knows where rates are heading. But being clear that you're making a bet — rather than banking a certainty — is the difference between a decision and a guess.
Other reasons people break
It isn't always about chasing a rate. Breaking also comes up when you're selling, moving banks for a cashback, restructuring across terms, or repaying a lump sum larger than your loan allows.
The maths is the same in each case — is the benefit bigger than the fee — but the benefit isn't always an interest saving. If you're moving banks for a cashback, weigh the cashback and the new rate together.
Which bank’s mortgage offer is best calculator?
Before you commit
Two things to check with your bank alongside the fee.
How long the quoted figure holds. Break costs move with wholesale rates, so a figure quoted on Monday may not be the figure on Friday.
Whether a cashback clawback applies. If you took a cashback when you set up the loan and you're inside the qualifying period, leaving may mean repaying some of it — on top of the break fee.
Worth talking through?
Break decisions come with a deadline and a number that feels large, which is a bad combination for clear thinking.
Get in touch for a free 30 minute chat. Independent, commission-free, and I don't get paid by any bank.