These are estimates and are kept separate from principal and interest.
Estimate voluntary overpayments. Check your lender for annual limits, fees, or early repayment charges.
Educational estimate only. Actual approval depends on lender criteria, credit profile, property, fees, and local rules.
A repayment mortgage splits each payment between interest and principal. Early payments usually contain more interest because the outstanding balance is higher. As the balance falls, more of each payment reduces principal.
Extra payments reduce the balance sooner, which means less interest accrues in later months. The calculator estimates the new payoff date and interest saved, but lender overpayment limits and fees can change the real result.
This tool models a repayment mortgage. Interest-only mortgages work differently: payments cover interest during the term and the borrowed principal must be repaid separately.
It includes principal and interest, and any optional monthly costs or overpayments you enter. It does not include lender fees, taxes that vary by location unless entered, rate changes, escrow rules, or lender-specific underwriting.
Formula/content last reviewed: July 5, 2026.
For a fixed-rate repayment mortgage, the calculator uses the standard amortization formula based on loan amount, monthly interest rate, and number of monthly payments.
Principal is the amount borrowed and repaid over time. Interest is the borrowing cost charged on the outstanding balance.
Principal and interest are calculated automatically. Taxes, insurance, mortgage insurance, HOA or service charge, and other ownership costs are included only if you enter them.
APR means annual percentage rate. This calculator treats the rate as a fixed annual interest rate for repayment estimates and does not add lender fees unless you include them separately.
A larger deposit reduces the mortgage amount and loan-to-value ratio, which usually lowers the monthly repayment and total interest.
Overpayments reduce the balance faster, which can cut the payoff date and reduce total interest. Check lender rules for limits or early repayment charges.
A repayment mortgage pays interest and gradually reduces principal. An interest-only mortgage pays interest during the term and leaves the principal to be repaid separately.
Lender quotes may include fees, daily interest rules, insurance, taxes, rate changes, rounding, eligibility criteria, or payment timing that this estimate does not model.
Yes. Choose the known mortgage amount option or remortgage mode and enter the current balance, rate, term, and start month for an estimate.
