Mortgage Repayment Calculator

Monthly payment = P × r ÷ (1 − (1 + r)^−n), where P is principal, r is nominal annual rate ÷ 12, and n is term in months.

Your inputs stay in your browser. No account required.

Compare your repaymentsOn your device

Loan amount (numbers only)

Annual interest rate (%)

Loan term (whole years)

Extra monthly repayment (same currency)

Scheduled monthly repayment

2,155.01 / month

Scheduled775,803.72

With extra repayments775,803.72

PrincipalInterest

Add an extra monthly repayment to see the difference.

See the exact comparison

Scenario	Interest	Months
Scheduled	425,803.72	360
With extra	425,803.72	360

Same currency as your input. Fixed rate, monthly payments, no fees or taxes. The chart compares total cost, not the changing loan balance.

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How Mortgage Repayment Calculator works

Monthly payment = P × r ÷ (1 − (1 + r)^−n), where P is principal, r is nominal annual rate ÷ 12, and n is term in months. The schedule rounds each monthly interest amount and payment to 0.01; extra repayments reduce principal immediately.

Try an example

A 100,000 loan at 6% over 30 years has a scheduled repayment of about 599.55 per month before extra repayments.

Good to know

Fixed-rate estimate with monthly payments at month-end. Excludes fees, taxes, insurance, escrow, offset accounts, rate changes and lender-specific rules. Results use the same currency units as the input and are not financial advice.

Your privacy

Processing happens on this device for this tool. We do not upload your input, put it in share links or save it to your favourites. Closing this tab discards the working input; downloaded results remain wherever you save them.

When this tool is useful

Use this estimator to explore how principal, rate, term and extra payments affect a scheduled repayment—not to obtain a lender quote.

How to use it

Enter the balance, nominal annual rate and term using the units shown.
Optionally add a recurring extra payment and compare the interest and time saved.
Record the assumptions and confirm fees, compounding and lender rules with the actual provider.

Checks before you rely on the result

The model uses fixed nominal APR with monthly compounding and cent-rounded scheduled payments.
It does not include taxes, insurance, fees, rate changes, redraw rules or lender-specific offsets.
Zero or invalid balances are rejected so an apparent answer is never silently fabricated.

This page is maintained with the tool implementation and its deterministic tests. If the result looks wrong, report the issue with a non-sensitive example.

Read the Mortgage Repayment Calculator instructions

A useful next step

Percentage Calculator

Percentage Change

Date Difference

Made for clarity. Built to be useful.Report an issue