Repayments Of Mortgage Calculator
Most borrowers think of their mortgage as a monthly payment, but lenders offer a choice that changes the rhythm of repayment: monthly, fortnightly, or weekly schedules. The frequency you choose affects payment size, payment count, interest accrual, and even payoff speed.
The Repayments Of Mortgage Calculator on this page computes repayments for any frequency. Enter loan amount, rate, term, and frequency to see repayment per period, number of payments, first-payment interest, total interest, and total of all repayments.
What Is a Mortgage Repayment?
A mortgage can be repaid monthly, fortnightly, or weekly. The math is identical: payment = P × rp / (1 − (1 + rp)^−n), where rp is the periodic rate and n is total payments. On $400,000 at 6.25% over 30 years: monthly $2,462.87 (360 payments), fortnightly $1,136.17 (780), weekly ~$568 (1,560).
Note: many lenders define fortnightly as half the monthly payment ($1,231.44 here vs formula's $1,136.17) — 26 halves = 13 monthly equivalents, adding an extra payment yearly that shortens the term by years. The calculator uses the exact formula; ask your lender which convention applies.
Why Payment Frequency Matters
Cash-flow alignment: fortnightly-paid workers budget best with fortnightly payments — fewer timing mismatches, fewer overdrafts. Interest timing: more frequent payments drop principal sooner; fortnightly saves ~$422 vs monthly on the example. Behavioral: smaller frequent payments feel manageable; half-monthly fortnightly = forced extra payment yearly.
How to Use the Calculator
Step 1: Enter Loan Amount (e.g., 400000).
Step 2: Enter Annual Interest Rate (e.g., 6.25).
Step 3: Enter Loan Term in years (e.g., 30).
Step 4: Choose Payment Frequency (Monthly/Fortnightly/Weekly).
Step 5: Click Calculate; compare frequencies side by side.
Worked Example: $400,000 at 6.25% Over 30 Years
Monthly: $2,462.87 × 360; first interest $2,083.33; total $886,632.77; interest $486,632.77. Fortnightly: $1,136.17 × 780; first interest $961.54; total $886,210.99; interest $486,210.99 (~$422 less). Half-monthly convention ($1,231.44) would shorten term by years.
Understanding Periodic Rates
Periodic rate = annual rate ÷ payments per year. Total payments = years × payments per year. More frequent = smaller periodic rate, smaller payments, more of them. Total is nearly identical; small differences come from timing.
Common Mistakes
- Assuming frequency saves a fortune. Exact-formula savings are small; big savings come from half-monthly extra-payment convention.
- Fighting your pay cycle. Match schedule to income rhythm.
- Ignoring per-payment fees. 52 weekly payments may cost more in fees.
- Underestimating annual total. 52 small payments ≈ 12 large ones.
Tips
- Match pay cycle.
- Ask lender's fortnightly convention. Half-monthly shortens term; exact keeps it.
- Compare total interest.
- Check per-payment fees.
- Automate on payday.
Frequently Asked Questions
1. How to calculate for different frequencies? Use periodic rate and payment count in the amortization formula.
2. Is weekly cheaper than monthly? Slightly — a few hundred dollars over 30 years on large loans.
3. Why isn't fortnightly exactly half of monthly? 26 fortnights divide the year differently than 12 months; lenders often charge exactly half anyway (overpaying).
4. Does frequency affect total interest? Modestly under exact formula.
5. Should I match my salary cycle? Usually yes — smoother cash flow.
CONCLUSION
The calculator lays every schedule bare. Choose deliberately: match frequency to pay cycle, understand your lender's convention, and remember real savings come from paying a little extra.