What does the home cost per month?
See what the home costs each month. Adjust the price and interest rate to find your buffer.
At least 10 % of the price
Power, heating, water, insurance, upkeep
Adjust rate
Default: SCB average rate on new mortgages, July 2026
Banks test you at 6–7 % to check you can handle a higher rate
How we calculate
The monthly cost is the figure you actually compare between homes, not the asking price. It has three parts: interest on the loan, amortisation (mandatory, but it is saving that cuts your debt) and running costs.
Amortisation follows your loan-to-value
If the loan is above 70 % of the home value you amortise at least 2 % of it a year, between 50 and 70 % at least 1 %, and below 50 % there is no requirement. Since 1 April 2026 the tightened requirement (an extra 1 % for large loans relative to income) is gone.
Always stress-test
Rates move. Tap the stress test to see the monthly cost at 6–7 %, the level the bank uses when assessing your application. If your budget survives that, you are on solid ground.
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Terms used here
Heimer does this for you
Paste a listing and get the monthly cost, the risks and what to check.
Run it on a real listing See a finished analysis