Extra Repayments Calculator Australia

Extras working hard? Make sure the loan underneath them is too.

A disciplined extra-repayment plan plus a sharper rate is often the winning combination. See if a better loan would amplify what your extras are already doing.

How this Extra Repayments Calculator works

An Extra Repayments Calculator compares your current path against a faster one where you pay more than the minimum. It then estimates how much sooner you could repay the loan and how much interest might be avoided by reducing the principal more quickly.

Interest is charged on whatever is still owing. When extra repayments reduce that amount earlier, future interest charges shrink because there's simply less debt to charge. That benefit compounds over time in your favour instead of only in the lender's.

The value isn't just in proving that extra repayments help. It's in making the scale of the help visible, so you can decide whether a slightly uncomfortable extra amount is worth the interest and years it could save.

This Extra Repayments Calculator is a guide, not a product manual. It:

• Assumes extra repayments are made consistently from the start of the loan you're modelling.
• Assumes the interest rate stays at the level you enter unless you change it.
• Estimates interest and time saved using a standard repayment schedule, not every lender's exact product rules.
• Does not automatically account for fixed-rate caps, prepayment limits, redraw restrictions or future changes to your required minimum repayment.

Extra repayments vs offset vs redraw

This is where a lot of confusion lives, so it's worth spelling out in plain language.

Extra repayments are often the purest way to attack the debt. Offset is often the most flexible. Redraw sits somewhere between the two. The right strategy depends on your appetite for flexibility, your product rules and how disciplined you are with accessible cash.

How to interpret your results

Don't read the result as a fantasy. Read it as a stress test for your discipline.

• Interest saved is meaningful. Your extra amount is doing real work.
• Years saved is large. You're hitting the loan early enough for time to become your ally rather than your enemy.
• The effect is modest. The extra amount may be too small, the loan may be far advanced, or you may need to combine this with a sharper rate or better structure.

The point isn't to pledge a heroic extra repayment that collapses after three months. The point is to find an amount that survives real life and still moves the needle.

How to find an extra repayment plan that lasts

Extra repayments are only smart if they're sustainable. A gorgeous spreadsheet that lasts three pay cycles is less valuable than a smaller, unremarkable extra amount that runs for a decade.

• Start with the minimum repayment from your existing loan or the Repayment Calculator.
• Add a small extra amount that feels achievable weekly, fortnightly or monthly — and test it here.
• Add a realistic lump sum if you expect bonuses, tax refunds or occasional windfalls, and test that scenario too.
• Compare those extra-repayment strategies with an offset-heavy approach if flexibility matters.
• If the calculator shows strong savings but your current loan is clunky or expensive, test a refinance scenario next.

The impulsive move is to promise yourself a giant extra repayment and then quietly abandon it. The wiser move is to choose an amount that survives rate rises, bad weeks and surprise bills. LoanGorilla is on the side of the plan that still exists six months from now.

Calculator assumptions

This calculator estimates time and interest saved by simulating a standard amortisation schedule with the entered extra repayment applied each period from the start, plus an optional one-off lump sum applied at the chosen month. The baseline scenario applies only the scheduled minimum repayment for the same balance, rate and term. The interest rate is assumed to hold for the full term unless changed manually. Fixed-loan prepayment caps, break costs, redraw rules, lender-specific repayment timing, package or ongoing fees and future rate movements are not modelled. The calculator does not constitute financial advice. Reviewed by the LoanGorilla editorial team — last updated May 2026.