Term is the quiet lever. Stretching a loan from 25 to 30 years can make a house feel affordable on paper while adding years of interest. Shortening it raises the repayment and cuts the total cost if you stick with it. The right answer is the one you can keep paying when life is average, not perfect.
Longer term, lower repayment, more interest
A 30-year term amortises the principal slowly in the early years. That protects cashflow and increases total interest. A 20-year term does the opposite. The mortgage calculator makes the trade-off visible in dollars per fortnight and total interest — use both numbers, not one.
Approval term versus personal target
Some buyers take the longest term the bank allows to maximise comfort under serviceability, then pay extra as if they were on a shorter term. That only works if the extra payments actually happen. A structured fortnightly surplus is more reliable than good intentions.
Rate risk grows with term
More years mean more refixes. A household that only works at the current rate on a 30-year loan is more exposed than one that still has headroom. Test the repayment at a higher rate before you congratulate yourself on the term that “fits.”
LVR and term interact
A smaller deposit (higher LVR above 80%) already raises loan size. Pairing high LVR with a maximum term stacks risk: bigger balance, longer interest clock, less room to err. Sometimes waiting for a larger deposit is cheaper than forcing a 30-year high-LVR shape.
The asymmetry between lengthening and shortening
These two moves are not mirror images, and the difference should shape your choice. Taking a longer term and paying extra voluntarily leaves you in control: the required payment stays low, and in a bad month you simply stop the extra without asking anyone. Taking a shorter term commits you contractually to the higher payment, and if things tighten you have to approach the lender to restructure — a conversation that is harder precisely when you most need it to go well. The shorter term does impose a discipline that some households genuinely need. But if you are confident you will make the extra payments, the longer term with extras gives you the same outcome with an escape hatch.
Term at refinance and later in the loan
Term is not decided once. Every refinance is a chance to reset it, and this is where people quietly lose years. Refinancing a loan with 22 years left back out to a fresh 30-year term lowers the payment and feels like a win, but it restarts the amortisation clock and can add more in interest than the better rate saves. If you refinance mainly for the rate, ask the lender to keep the remaining term rather than defaulting to a new maximum. Conversely, if your income has grown, a refinance is a natural moment to shorten deliberately.
Practical approach
Model 20, 25 and 30 years at the same rate. Keep the term whose higher-rate stress test you can still pay, then decide whether extras will simulate a shorter term. That order — survival first, optimisation second — avoids painting yourself into a corner.
One caution when reading the totals. The lifetime interest figure on a 30-year loan assumes you keep that loan, at that rate, for three decades, which almost nobody does. Most borrowers sell, refinance or repay early well before the term ends. Treat total interest as a way of ranking the options against each other rather than a prediction of what you will pay, and give more weight to the repayment figure — that is the number you have to meet every fortnight, and it is the one the bank will test.