Mortgage Calculator
A monthly payment, total interest and year-by-year schedule, in seconds — no spreadsheets needed.
Buying a home is a big call, and the monthly payment is the number that matters most. Put in the price, deposit, rate and term, and this mortgage calculator works out the rest — for the US and UK alike.
How this mortgage calculator works
Most US and UK home loans are repayment mortgages — sometimes called fully amortizing. Your payment stays the same each month. Interest for that month comes off first, and what is left chips away at the balance. So early on, interest takes most of the payment; later, principal takes more.
Here is the standard formula behind the monthly payment:
M = P × r ÷ (1 − (1 + r)−n)
- P is the amount you borrow (home price minus your down payment)
- r is the monthly interest rate (the annual rate ÷ 12 ÷ 100)
- n is the number of monthly payments (years × 12)
Worked example
Take a $350,000 home and a $70,000 (20%) down payment. That leaves a $280,000 loan over 25 years at 6.5%, with a monthly payment of $1,890. Over the full term you would pay roughly $287,000 in interest — slightly more than you borrowed. Shorten that same loan to 15 years and the payment rises to about $2,439, but total interest falls to roughly $159,000, a saving of around $128,000.
US vs UK mortgages: what's different?
- Term and rate type. In the US the 30-year fixed-rate mortgage is the norm. In the UK most borrowers fix for 2 to 5 years and then remortgage, usually over a 25 to 35 year term.
- Property tax and insurance. US lenders often collect property tax and homeowner's insurance with your payment through an escrow account. UK buyers pay council tax and insurance separately, so leave those boxes at zero.
- Deposit and PMI. In the US, putting down less than 20% usually means paying private mortgage insurance (PMI). In the UK a smaller deposit (a higher loan-to-value) usually means a higher interest rate.
Tips to lower your monthly payment
- A bigger deposit helps. Each step down in loan-to-value can unlock a better rate.
- Compare lenders. A 0.5% difference in rate on $280,000 over 25 years is worth tens of thousands.
- Overpay when you can. Even small regular overpayments shorten the term and cut interest. (Check your lender's overpayment limits first.)
Frequently asked questions
Does this include PMI or HOA fees?
No. Add these to the insurance box (as a yearly figure) for a rough all-in monthly cost.
Can I use this for an interest-only mortgage?
No. For an interest-only loan, the monthly payment is simply loan amount × annual rate ÷ 12, and the full balance is still owed at the end of the term.
How accurate is the result?
The maths matches what lenders use for a fixed-rate repayment loan. Your real payment may differ slightly because of fees, rounding and the exact date your first payment is due.
This calculator gives estimates for information only. Speak to a licensed mortgage adviser or lender before you make a decision.