Advanced mortgage calculator with a full amortization schedule and extra payment impact. Estimate your monthly payment, payoff date, total interest, and interest saved.
This mortgage calculator estimates your monthly payment using your loan amount, interest rate, and repayment term. It shows the split between principal and interest, builds an amortization schedule, and lets you test overpayments to see how much interest you could save and how much sooner you may become mortgage-free. That makes it useful whether you are buying your first home, comparing fixed-rate offers, or reviewing whether a remortgage could lower your monthly cost.
Practical tips: compare a shorter vs longer term to see the trade-off between monthly affordability and total interest; test one realistic overpayment amount such as £50 to £200 per month; and run a slightly higher interest rate to stress-test your budget before committing. If your mortgage also includes property tax, insurance, or service charges, use this result as the base loan payment and then add those housing costs for a more complete monthly figure.
What this mortgage calculator does best: it helps you compare loan scenarios quickly, understand how amortization works, and see the long-term cost of borrowing instead of focusing only on the headline monthly payment. Small changes in rate, term, and overpayments can make a large difference to total interest paid over the life of the loan.
Important limitations: results are estimates based on fixed assumptions, regular payments, and stable rates. Real lender calculations can differ because of fees, changing rates, rounding methods, escrow, and local tax rules. If your situation changes, rerun the calculator with updated numbers and check the final figures against your lender’s official illustration.
If you’re remortgaging, use the calculator to estimate how a new rate changes your monthly cost, then keep a buffer for unexpected maintenance, rate resets, and general household expenses so the payment still fits your wider budget.
Add real-life costs (tax, insurance, HOA) and optionally an extra monthly payment to see how fast you can pay off the mortgage.
Updated when you click Calculate.
Shows the first 24 months for readability. Your totals still use the full schedule.
| Month | Payment | Principal | Interest | Extra | Balance |
|---|---|---|---|---|---|
| Click Calculate to generate your amortization schedule. | |||||
A good mortgage calculator is most useful when you compare more than one scenario. Start by testing the same loan amount across two different terms, such as 25 years and 30 years. Then compare at least two interest rates so you can see how sensitive the payment is to small rate changes. This helps you avoid choosing a deal based only on the lowest initial monthly cost.
You should also compare the total interest paid, not just the monthly payment. A longer term can look easier each month but may cost much more over time. Adding a modest recurring overpayment can sometimes save thousands in interest and shorten the mortgage by years, which is why this calculator includes both amortization and extra payment testing.
For a realistic budget, treat the loan payment as one part of the full housing cost. Property taxes, insurance, maintenance, utilities, and service charges all affect affordability. After testing scenarios here, use a budget planner calculator to check whether the payment still works with your wider monthly cash flow. If you are deciding between buying and waiting, use the calculator more than once with conservative assumptions so your plan still works if rates stay higher for longer.
We calculate your principal+interest payment using standard amortization math, then simulate month-by-month to apply extra payments and compute the payoff date and interest saved.
Yes, as long as your payment covers the monthly interest. Extra payments reduce principal directly, which reduces future interest and shortens the schedule.
If your principal+interest payment is less than or equal to monthly interest, the balance won’t decrease. Increase your payment, extend term, or lower the rate.
The schedule is for the loan balance (principal & interest). Tax/insurance/HOA are shown in your “all-in” monthly cost but don’t reduce loan principal.
This calculator uses standard financial formulas and simplified assumptions (for example: constant rates, regular payments, and rounding). Real-world results can differ due to fees, taxes, rate changes, compounding conventions, and account rules.
See how we build and validate our tools: Calculator Methodology. For how we review content: Editorial Policy.
Use these tools together for better planning and realistic cash-flow decisions.
It estimates your monthly mortgage payment based on the loan amount, interest rate, and term using standard amortization formulas.
This tool focuses on principal and interest. Property taxes, insurance, HOA fees, and other costs can increase the real monthly payment.
A longer term usually lowers the monthly payment but increases total interest paid. A shorter term costs more monthly but can save interest.
Overpayments usually reduce interest and can shorten the term by reducing the principal faster, depending on lender rules.
Fixed rates keep payments stable. Variable rates can change over time, which can raise or lower payments and total interest.