Mortgage Calculator
Monthly payment, total interest, amortisation schedule and overpayment savings.
About this tool
Price, deposit, rate and term give the monthly payment, loan-to-value, total interest and total repaid; the schedule shows every year (or month); an optional overpayment shows the years and interest it saves. Nothing is stored.
The numbers behind the monthly figure
A repayment mortgage charges interest on the outstanding balance each month, so early payments are mostly interest and late ones mostly capital โ the amortisation curve in the chart โ and the total interest over 25 or 30 years is often comparable to the amount borrowed. That is also why overpaying early matters so much more than overpaying late: money paid against the balance in year two stops earning interest for the lender for the rest of the term, and a modest regular overpayment typically cuts years off. Honest scope: this is the loan arithmetic only. Arrangement fees, insurance, property tax, service charges, fixed-rate periods that revert to a different rate, and lenders' rounding are outside it; affordability depends on income, stress tests and your other commitments, which no calculator sees; and early-repayment charges can apply to overpayments on fixed deals โ check before paying extra. General information, not advice. The loan calculator covers car and personal loans, compound interest the savings side, and Compound interest, explained with real numbers the mechanism.
Frequently asked questions
How is the monthly payment calculated?
The standard annuity formula: the loan times the monthly rate, divided by one minus (1 + monthly rate) to the power of minus the number of months. Lenders round slightly differently.
Does overpaying really help?
Yes, especially early: extra money reduces the balance interest is charged on for the rest of the term. Enter an amount to see the years and interest saved โ and check your deal for early-repayment charges first.
What is LTV?
Loan-to-value: the loan as a percentage of the price. Lower LTV usually unlocks better rates; the calculator shows yours from price and deposit.
Is this financial advice?
No โ it is the arithmetic of a repayment loan, for information. Fees, insurance and rate changes are not included; speak to your lender or a regulated adviser before deciding.