Finance & Property · Introduction
Mortgage Calculator
Estimate payments. The model’s fixed 50% DSR is not a local lending approval limit.
Updated 2026-10-25 · ThinkVault Tools
What can this tool help you do?
Estimate payments. The model’s fixed 50% DSR is not a local lending approval limit.
Check the purpose and assumptions, then open the tool. Return to the guide for details.
How is a mortgage payment calculated?
How is a mortgage payment calculated?
This tool uses the level-payment (annuity) method: every instalment is the same, but early payments are mostly interest. As the balance falls, a growing share goes to principal. Results include the monthly payment, total interest and total repayment, plus the first 24 rows of the amortisation schedule.
50% DSR and the rate-rise scenario are different things
DSR compares monthly debt payments with monthly income. This tool fixes 50% as an illustrative assumption and calculates reference income as current-rate payment ÷ 50%. It is not a statutory limit, a safe affordability level or loan eligibility in any jurisdiction. Lenders also consider other debts and individual terms.
Rate-rise scenarios are custom risk comparisons, not an official stress test or a lending decision. Check the latest rules in your location.
Method
Level monthly payments; after a teaser period, re-amortise the balance at the effective rate. Fixed illustrative reference income = current-rate payment ÷ 50%. The 50% assumption is not a jurisdiction’s approval rule; taxes, fees and eligibility are not applied automatically.
Last checked: 2026-10-24
Before you begin
Tax, lending, holiday and protection rules vary by place and date. Check current local rules and provider terms. Results are estimates.