Home Loan Extra Repayments Calculator
Enter your loan balance, interest rate, remaining term and an extra amount per repayment to see the time and interest saved against the scheduled loan. The scheduled loan uses the same amortised calculation as the rates in our tables. Estimate only, not credit advice.
$500,000 over 30 years at 6.00% p.a., with an extra $200 a month
Interest saved against the scheduled loan
- Time saved
- 4 years 6 months
- Interest saved
- $103,145
- Paid off in
- 25 years 6 months
- Scheduled repayment
- $2,998 a month
- Scheduled interest
- $579,191
- Interest with extra
- $476,046
Estimate only, based on an amortised principal and interest loan with monthly repayments, at the rate you entered for the whole term. The extra amount is assumed to be paid with every repayment and never redrawn. Fees are not included, and loan features and limits vary by lender. This is general information, not credit advice.
- With extra repayments
- Scheduled loan
How we calculate this
The formula
- B
- the balance at the start of the month
- r
- the monthly interest rate, which is the annual rate divided by 12
- M
- the scheduled monthly repayment
- E
- the extra amount paid with each repayment
- P
- the balance today
- n
- the scheduled number of monthly repayments left
The repayment is sized on the balance and term, the same as our Home Loan Repayment Calculator, and the results compare against that schedule:
- M equals P times r times one plus r, to the power n, all divided by one plus r, to the power n, minus one
- Scheduled interest = M × n − P
- Interest saved = Scheduled interest − the interest charged until B reaches zero
- Time saved = n − the months until B reaches zero
What we assume
- The extra is paid with every repayment. The same extra amount goes in every month until the loan clears, and none of it is taken back out through redraw. A one-off lump sum is not modelled.
- The loan allows it. Many fixed rate loans limit extra repayments or charge for going over a limit, and this calculator applies no limit. Check the terms of your own loan.
- The rate never changes. The rate you enter is applied for the whole term. A variable rate will move, and a fixed rate reverts at the end of the fixed period, and either would change these figures.
- Fees are excluded. Account and package fees are not included, nor are any break costs. A fee would reduce what is saved.
- Monthly repayments, charged monthly. Interest is worked out once a month on the balance at the start of the month. Lenders usually calculate it daily and charge it monthly, so a real loan will differ a little.
- A part month counts as a month. Time saved is counted in whole monthly repayments. The last repayment is only what is still owing, which can save some interest without taking a full month off the term.
A worked example
A home loan balance of $500,000 at 6.00% p.a. with 30 years to run, and an extra $200 with each monthly repayment.
- Work out the scheduled repayment$500,000 over 360 months at 6.00% p.a.M = $2,997.75 a month
- Work out the first month’s interest$500,000 × 0.005000$2,500.00 of interest
- Take off the repayment and the extra$500,000 + $2,500.00 − ($2,997.75 + $200)$499,302.25 owing after month one
- Repeat each month until nothing is owingThe same step on the new balance, adding up the interest as it goes306 months, and $476,046 of interest
- Compare with the scheduled loan$579,191 − $476,046, and 360 − 306 months$103,145 of interest and 54 months saved
Figures above are rounded for reading, so a line can differ by a dollar from the exact arithmetic. The calculator itself works to full precision.
Paying an extra $200 a month on $500,000 at 6.00% p.a. clears the loan in 25 years 6 months rather than 30 years, with $103,145 less interest.