What does this tool do?
The Mortgage Calculator works out your monthly payment and the total interest you will pay over the life of a home loan, based on the loan amount, annual interest rate and term. It is built for anyone weighing up a property purchase or thinking about refinancing an existing mortgage.
How to use it
- Enter your values into the fields.
- The result is calculated instantly.
- Read or copy the result.
How it works
The calculator uses the standard amortizing loan formula: your fixed monthly payment depends on the principal, the monthly rate (the annual rate divided by 12) and the number of payments. Enter a $300,000 loan at 5% over 30 years and you instantly see the monthly figure plus the total interest across 360 payments. Splitting principal from interest reveals the true cost of borrowing, not just the headline rate.
Practical tips
Shortening the term raises the monthly payment but dramatically cuts total interest, while a longer term eases the monthly strain at a higher overall cost. Compare scenarios side by side, such as a 15-year versus a 30-year loan, to find the balance that fits your budget. A larger down payment lowers the principal, reducing both the monthly payment and the lifetime interest.
Frequently asked questions
How is the monthly payment calculated?
Using the amortizing (annuity) method, where the loan amount, the monthly interest rate and the total number of months produce one fixed payment. Early payments are mostly interest; later payments are mostly principal.
What does total interest mean?
It is the sum of all your payments over the term minus the original loan amount, in other words the extra you pay the lender for borrowing the money.
Does it include taxes and insurance?
No. The result covers principal and interest only. Property taxes, homeowners insurance and lender fees vary by location and provider and are not part of the figure shown.
Is Mortgage Calculator free?
Yes. Mortgage Calculator and all 300+ tools on MagmaNex are completely free with no signup or account required.
Is my data safe?
Yes. Everything runs locally in your browser. The data you enter is never sent to a server, stored, or shared.
Does it work on mobile?
Yes. Mortgage Calculator works on phones, tablets and desktops — no app download needed.
🔒 Privacy: everything runs in your browser, your data is never sent to a server.