Mortgage · Calculator
Extra Mortgage Repayment Calculator
See how extra repayments and lump-sum payments cut interest and shorten the loan term on an Australian mortgage. Compare the interest saved and years trimmed from your loan.
Interest savedYears trimmedLump sum + regular
01 —INPUTS
Adds on top of every scheduled payment.
One-off lump sum (optional)
02 —RESULTS
Monthly repayment$3,062.34
Interest saved vs no extras$108,828
Payments saved vs no extras55 monthly payments
Total interest with extras$493,616
Total interest baseline (no extras)$602,444
Payoff time with extras25.4 years
03 —BREAKDOWN
Amortisation with extras applied
| Period | Payment | Principal | Interest | Balance |
|---|---|---|---|---|
| 1 | $3,262.34 | $679.01 | $2,583.33 | $499,320.99 |
| 2 | $3,262.34 | $682.52 | $2,579.83 | $498,638.47 |
| 3 | $3,262.34 | $686.05 | $2,576.30 | $497,952.42 |
| 4 | $3,262.34 | $689.59 | $2,572.75 | $497,262.83 |
| 5 | $3,262.34 | $693.15 | $2,569.19 | $496,569.68 |
| 6 | $3,262.34 | $696.73 | $2,565.61 | $495,872.94 |
| 7 | $3,262.34 | $700.33 | $2,562.01 | $495,172.61 |
| 8 | $3,262.34 | $703.95 | $2,558.39 | $494,468.66 |
| 9 | $3,262.34 | $707.59 | $2,554.75 | $493,761.07 |
| 10 | $3,262.34 | $711.25 | $2,551.10 | $493,049.82 |
| 11 | $3,262.34 | $714.92 | $2,547.42 | $492,334.90 |
| 12 | $3,262.34 | $718.61 | $2,543.73 | $491,616.28 |
| 300 | $3,262.34 | $3,170.02 | $92.32 | $14,698.59 |
| 301 | $3,262.34 | $3,186.40 | $75.94 | $11,512.19 |
| 302 | $3,262.34 | $3,202.87 | $59.48 | $8,309.32 |
| 303 | $3,262.34 | $3,219.41 | $42.93 | $5,089.91 |
| 304 | $3,262.34 | $3,236.05 | $26.30 | $1,853.86 |
| 305 | $1,863.44 | $1,853.86 | $9.58 | $0.00 |
FAQ
Will every extra dollar reduce interest?
Effectively yes — extra principal reduces the balance, and interest each period is a percentage of the remaining balance, so a smaller balance compounds into less total interest over the life of the loan.
Should I make one large lump sum or small extras over time?
Earlier payments save more interest because they reduce the balance for more periods. A lump sum near the start of the loan saves more than the same amount near the end. If both are options, doing both compounds the savings.
Are extra repayments restricted on fixed-rate loans?
Often yes — many fixed-rate products cap extra payments per year (commonly $10,000 or 5% of the loan balance). Check your product disclosure or talk to your lender before assuming you can pay any amount. Variable-rate loans generally have no cap on extra repayments.
Is it better to put savings in offset or make extra repayments?
Both have the same interest-saving effect dollar-for-dollar. Offset preserves liquidity — you can withdraw at any time. Extra repayments reduce your available redraw unless your loan includes a redraw facility. For most owner-occupiers, offset is the safer default; extra repayments make sense when you're certain you won't need the cash.