Translate one loan across repayment frequencies
Monthly, fortnightly and weekly repayment amounts are not simple divisions of each other because each schedule has a different number of periods and periodic interest rate. This calculator produces equivalent level principal-and-interest payments for the same loan amount, rate and term.
Use the figures to plan cash flow, not to assume a lender’s debit amount. Lenders can calculate interest daily, choose specific debit dates, round repayments, or offer fortnightly arrangements that are not an equivalent periodic schedule. Ask whether a proposed frequency changes the annual amount paid or simply changes the timing of the same contractual repayment.
How to read the results
Equivalent fortnightly repayment is the headline amount due every 26 periods a year. Monthly repayment and Weekly repayment show the corresponding level payment for 12 and 52 periods respectively under the same nominal annual rate.
Monthly annual total multiplies the monthly amount by 12. The chart compares annual totals for all three frequencies. Small differences arise because each frequency compounds and amortises at a different periodic rate; it is not a saving projection for paying half a monthly amount every fortnight.
Worked example
Using the default $650,000 loan, 6.34% interest rate and 30-year term, the calculator gives an equivalent fortnightly repayment of $1,863.86. The monthly repayment is $4,040.29 and the weekly repayment is $931.74.
The monthly annual total is $48,483.44. These are separately calculated schedules with the stated period counts, rather than one repayment simply divided into smaller instalments.
Confirm the lender’s actual debit amount before setting up an automatic transfer or household budget.
Assumptions and limitations
- Each schedule amortises the full loan over the entered term.
- The nominal annual rate remains constant.
- There are 12 monthly, 26 fortnightly and 52 weekly repayment periods each year.
- No fees, offset balance, redraws or additional repayments are included.
- Lender daily-interest calculations and calendar cut-offs are not replicated.
Frequently asked questions
Is fortnightly always half the monthly repayment?
No. An equivalent 26-payment schedule is calculated independently and may differ from half the monthly amount.
Will weekly payments reduce my interest?
That depends on the lender’s interest and payment timing rules; this tool compares equivalent schedules, not a specific lender’s process.
Which amount should I budget for?
Use the frequency your lender accepts and confirm its quoted repayment and debit calendar.
This calculator and supporting information provide general estimates only. They do not take account of every product rule, tax consequence or personal circumstance and are not financial, tax, credit or legal advice.