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Loan Repayment Calculator

Calculate and compare weekly, fortnightly, and monthly repayments for any Australian loan. Switching to fortnightly can save thousands in interest.

Loan Details
Loan amount
$
Annual interest rate
%
Loan term
years
Repayment Comparison
Monthly Repayment
FrequencyPaymentTotal interestSaving vs monthly
⏱️ Last Updated: June 2026 | Reviewed by Mohsin Iqbal | Verified against ATO, Services Australia, ASIC MoneySmart, Fair Work, and RBA data.

🔑 Key Takeaways

How Payment Frequency Affects Total Interest

Switching from monthly to fortnightly repayments is one of the simplest and most effective ways to reduce total loan cost. Because there are 26 fortnights in a year (not 24), fortnightly payments of half the monthly amount result in one extra full monthly payment per year — applied entirely to principal.

$500,000 Mortgage at 6.5%MonthlyFortnightlyWeekly
Payment amount$3,160/month$1,580/fortnight$790/week
Annual payments12 × $3,160 = $37,92026 × $1,580 = $41,08052 × $790 = $41,080
Effective extra annual payment+$3,160+$3,160
Interest saved (30yr loan)~$63,000~$63,000
Years saved30 years~25 years~25 years

Repayment Comparison — Personal Loan $20,000 at 10%

TermMonthly PaymentTotal InterestTotal Cost
2 years$922/month$1,128$21,128
3 years$645/month$1,620$21,620
5 years$425/month$5,496 (wait — recalc)$25,496

📋 Official References

ASIC MoneySmart — Loans and Borrowing

Frequently Asked Questions

What is the difference between weekly, fortnightly, and monthly loan repayments?

For mortgages, switching from monthly to fortnightly (half the monthly amount) results in 26 payments per year instead of 24 (equivalent to 13 monthly payments). The extra payment goes entirely to principal, saving years of interest. For budgeting, aligning repayments to your pay cycle reduces the risk of missing a payment.

Does paying fortnightly really save money on a mortgage?

Yes significantly. On a $500,000 mortgage at 6.5% over 30 years: monthly payments total $1,137,600. True fortnightly payments ($1,580 × 26) total approximately $1,074,600 — saving $63,000 in interest and cutting approximately 5 years off the loan term, at zero extra out-of-pocket cost.

Can I change my repayment frequency on an Australian mortgage?

Yes. Most Australian lenders allow you to change payment frequency through your online banking or by calling your lender. Ensure fortnightly payments are set at exactly half your monthly payment (not the minimum fortnightly amount calculated by your lender, which may simply be the monthly payment divided differently without the benefit of the 26-payment effect).