Repayment On Mortgage Calculator
Before you sign a mortgage, one number matters more than any other: your repayment. It determines whether the loan fits your budget and how much the property really costs once interest is included.
The Repayment On Mortgage Calculator on this page converts loan amount, rate, and term into monthly, fortnightly, weekly, and annual repayments, plus total interest and total repayment.
What Is a Mortgage Repayment?
A mortgage repayment is the regular payment to gradually pay off a home loan. Each payment splits into interest (lender's charge on the balance) and principal (reduces amount owed). Early on, interest dominates; later, principal grows — this is amortization.
Payment size is set by loan amount, rate, and term: M = P × r / (1 − (1 + r)^−n). Fortnightly payments (half-monthly every 2 weeks = 26 halves/year = 13 monthly equivalents) shorten the term noticeably.
Why Your Repayment Matters
$500,000 at 6.5% over 30 years = $3,160.34/month, $37,924/year, and $637,722 total interest — exceeding the amount borrowed. Lenders apply serviceability tests (income vs repayment + 2–3% buffer). Comparing terms reveals trade-offs: shorter term = higher payment but far less interest.
How to Use the Calculator
Step 1: Enter Loan Amount (e.g., 500000).
Step 2: Enter Annual Interest Rate (e.g., 6.5).
Step 3: Enter Loan Term in years (e.g., 30).
Step 4: Click Calculate; read Monthly, Fortnightly, Weekly, Annual, Total Interest, Total Repayment.
Worked Example: $500,000 at 6.5% Over 30 Years
Monthly: $3,160.34. Annual: $37,924.08. Fortnightly: $1,458.62. Weekly: $729.31. Total repayment: $1,137,722. Total interest: $637,722.
Understanding the Formula
M = P × r / (1 − (1 + r)^−n): the lender needs a payment stream whose present value equals the amount lent. Small rate changes move payments nonlinearly — 1% on a large 30-year loan shifts monthly payment by hundreds.
Key Factors
Rate is the most powerful lever. Term trades monthly affordability vs lifetime cost. Loan amount scales proportionally. Fees/features (offset, redraw) shift effective cost — compare the comparison rate.
Tips
- Budget on the monthly figure with a 2% rate-rise buffer.
- Compare total interest, not just payment.
- Test rate-rise scenarios (+2–3%).
- Consider fortnightly (13 monthly/year).
- Match pay cycles to reduce missed payments.
- Check comparison rate for fair comparisons.
Frequently Asked Questions
1. How is repayment calculated? M = P × r / (1 − (1 + r)^−n).
2. Why is my first payment mostly interest? Interest is charged on the largest balance at the start.
3. Are fortnightly repayments cheaper? 26 halves = 13 monthly; the extra payment shortens the term.
4. 20-year or 30-year term? 20-year = higher payment, far less interest; 30-year = easier monthly, much costlier.
5. Does it include taxes/insurance? No — principal and interest only.
CONCLUSION
The calculator converts any loan into six defining numbers. Look past the monthly payment to total interest — two loans can feel identical monthly yet differ by hundreds of thousands over their lifetimes.