Mortgage Calculator
Calculate principal-and-interest home loan repayments from your balance, rate and remaining term. Compare payment frequencies and see how extra repayments change the interest and payoff date.
Loan details
The example rate is hypothetical. Enter the loan's interest rate, excluding comparison-rate fees.
360 months is 30 years.
The first payment falls one repayment period after this date.
Paid separately each period. It adds to cash outflow without reducing the loan.
Extra repayments
Converted to an annual budget, then spread equally across your scheduled payments. This models a regular budget, not separate extra-payment dates.
Results
Correct the marked input to calculate repayments.
Scheduled repayment
$3,597.30
Principal and interest, before extras and feesTotal interest
$588,337.80
With your extra repaymentsLoan paid off
1 Dec 2052
Estimated final payment dateInterest saved
$106,693.55
Compared with no extra repayments313 monthly payments remain, compared with 360 without extras. Regular cash outflow is $3,797.30 including extras and fees. Total paid is $1,188,337.80.
Balance over time
The same loan with your extra repayments and without them.
The starting balance is $600,000.00. The loan takes 313 payments with the entered extra repayments, compared with 360 without extras.
Compare payment frequencies
Same balance, rate and term. Base repayments exclude extras and fees. Annual amounts use 12, 26 or 52 payments.
| Frequency | Base repayment | Annual repayments |
|---|---|---|
| Monthly | $3,597.30 | $43,167.60 |
| Fortnightly | $1,659.50 | $43,147.00 |
| Weekly | $829.58 | $43,138.16 |
Dated repayment schedule
Payment includes principal and interest. Fees are separate. Export CSV for every payment.
| Date | Payment | Principal | Interest | Fee | Balance |
|---|---|---|---|---|---|
| 1 Dec 2026 | $3,797.30 | $797.30 | $3,000.00 | $0.00 | $599,202.70 |
| 1 Jan 2027 | $3,797.30 | $801.29 | $2,996.01 | $0.00 | $598,401.41 |
| 1 Feb 2027 | $3,797.30 | $805.29 | $2,992.01 | $0.00 | $597,596.12 |
| 1 Mar 2027 | $3,797.30 | $809.32 | $2,987.98 | $0.00 | $596,786.80 |
| 1 Apr 2027 | $3,797.30 | $813.37 | $2,983.93 | $0.00 | $595,973.43 |
| 1 May 2027 | $3,797.30 | $817.43 | $2,979.87 | $0.00 | $595,156.00 |
| 1 June 2027 | $3,797.30 | $821.52 | $2,975.78 | $0.00 | $594,334.48 |
| 1 July 2027 | $3,797.30 | $825.63 | $2,971.67 | $0.00 | $593,508.85 |
| 1 Aug 2027 | $3,797.30 | $829.76 | $2,967.54 | $0.00 | $592,679.09 |
| 1 Sept 2027 | $3,797.30 | $833.90 | $2,963.40 | $0.00 | $591,845.19 |
| 1 Oct 2027 | $3,797.30 | $838.07 | $2,959.23 | $0.00 | $591,007.12 |
| 1 Nov 2027 | $3,797.30 | $842.26 | $2,955.04 | $0.00 | $590,164.86 |
Constant rate, with interest charged each repayment period. Fees are paid separately. This estimate excludes offsets, redraws, interest-only periods and balloon payments.
Weekly and fortnightly models use 52 and 26 periods per year. Their dates advance by 7 and 14 days, so model years contain 364 days. Monthly dates retain the chosen day where possible. Weekends and holidays do not move payment dates.
PDF prints the visible schedule page. CSV contains the full schedule. Your entries stay in this browser.
Mortgage Repayment Formula
A principal-and-interest repayment covers the period's interest and pays down part of the loan balance. The standard formula is A = P × r ÷ (1 − (1 + r)−n). P is the balance, r is the rate per payment period and n is the number of payments. At zero interest, A = P ÷ n.
Divide the annual percentage rate by 100, then by 12 for monthly payments, 26 for fortnightly payments or 52 for weekly payments. This calculator recalculates the repayment for each frequency. It rounds a partial final period up to a whole payment period.
Halving a monthly payment and paying it fortnightly creates 26 half-payments, equal to 13 monthly payments per year. That pays more each year than dividing the monthly amount by 26 and multiplying by 12. The comparison table shows each frequency on the same annual basis.
The same formula works for a simple business loan with regular principal-and-interest payments at a constant rate. Balloon payments or irregular drawdowns need a different model. Business cash-flow borrowing capacity and lender approval require a separate assessment.
Extra Repayments and Loan Amortisation
Extra repayments, also called overpayments, reduce principal sooner. Later interest is charged on the smaller balance. The scheduled base repayment stays the same, so the loan ends earlier.
For the starting $600,000 loan at 6% over 360 months, the base monthly repayment is $3,597.30. With no extras, estimated interest totals $695,031.35. Adding $200 per month reduces it to $588,337.80 and clears the loan in 313 payments, saving $106,693.55.
When the extra budget has a different frequency, the calculator spreads its annual value across the scheduled payments. A $100 weekly budget becomes $5,200 a year, or about $433.33 per monthly payment. Actual separately dated extras can produce a different result.
Using Bank and Moneysmart Calculators
For repayment comparisons involving Westpac, CBA or CommBank, ANZ, St.George, Suncorp, AFG, Aussie or Mortgage Choice, enter the loan's rate and fees. The public amortisation formula applies to regular principal-and-interest loans. A provider's calculator can use different payment dates, fee treatment or daily interest assumptions.
Moneysmart's mortgage calculator also assumes a constant rate and interest compounding at the selected repayment frequency. This tool uses your entered rate throughout. Change it to compare the payment commitment after a rate rise.
A repayment estimate is separate from borrowing approval or a product quote. Your actual account balance depends on transactions, lender rounding and the loan's interest rules. Use the estimated payments to compare scenarios on consistent inputs.
Reading the Repayment Schedule
In the starting example's first row, the payment is $3,797.30. Interest is $3,000.00, principal is $797.30 and the closing balance is $599,202.70. Subtract principal from the opening balance to obtain that closing balance.
Each row shows the payment date, and the final row gives the payoff date. The results state how many payment periods remain with your extra budget. Change the commencement date to move the dated schedule while keeping the same repayment assumptions.
Money rounds to cents each period. The final payment clears the remaining balance plus interest and usually falls below the regular amount. Without extra repayments, accumulated rounding can make the final payment slightly larger. Fees increase total cash paid without reducing principal.