Mortgage Calculator

How to use the Mortgage Calculator

Enter the property price and your deposit. The amount borrowed is the difference.
Add the interest rate, term, and your estimated annual property tax and insurance.
Optionally add a monthly overpayment to see how much interest it saves and how many years it removes.

What makes up a mortgage payment

A lender quotes principal and interest, but the amount leaving your account each month is usually larger. In the United States the shorthand is PITI:

Principal — repaying what you borrowed
Interest — the cost of borrowing it
Taxes — property tax, often collected monthly into an escrow account
Insurance — buildings insurance, plus mortgage insurance if your deposit is small

Not included here: service charges or HOA fees, ground rent, maintenance, and the closing or completion costs due at purchase. A common planning rule is to budget around 1% of the property value each year for maintenance.

Why the deposit matters more than the rate

Loan-to-value is the loan divided by the property price. Cross above 80% and most lenders require mortgage insurance — a monthly premium that protects the lender, not you, and can add a meaningful amount to the payment for years.

Loan-to-value also determines which rate tier you are offered. Moving from an 85% to an 80% loan often unlocks a better rate and removes the insurance, so the effective return on the extra deposit is larger than it first appears.

The arithmetic of overpaying

An extra payment goes entirely to principal, so it removes not just that amount but every future interest charge that balance would have generated. On a 30-year mortgage the effect compounds dramatically — a modest monthly overpayment can remove several years from the term.

Before committing, check two things: whether your agreement has early repayment charges, and whether your lender applies overpayments to principal immediately or holds them against the next scheduled payment. The second makes a real difference.

Frequently asked questions

Is this what a lender will offer me?

No. It shows the arithmetic of a loan with the figures you enter. An actual offer depends on income, credit history, affordability testing, the valuation and the lender's own criteria.

Does it include mortgage insurance?

No, but it warns you when your loan-to-value exceeds 80%, which is the usual threshold. Premiums vary widely by lender and country, so add yours to the insurance field.

How much house can I afford?

A common guideline is that housing costs stay under 28% of gross income and all debt under 36%. These are rules of thumb — lenders in different countries test affordability differently.

Should I choose a 15-year or 30-year term?

A 15-year term has much higher monthly payments but far less total interest. The 30-year gives flexibility: you can overpay to mimic a shorter term while keeping the option to fall back to the lower payment.