Work out your monthly mortgage payment before you buy. Enter the home price, down payment, loan term and interest rate to see your monthly payment, total interest and total cost, including property tax and home insurance if you add them.
Mortgage Calculator
How the Mortgage Calculator Works
This calculator estimates the full monthly cost of buying a home, not just the loan itself. People use it when comparing homes at different prices, testing how a bigger down payment changes the payment, or checking whether a shorter term is worth the higher monthly amount. Alongside the monthly figures, it shows the total interest over the life of the loan and the total cost of the purchase, which are the numbers that often surprise buyers most.
The loan part uses the standard fixed-rate mortgage formula: M = P × r(1 + r)^n ÷ ((1 + r)^n − 1). Here P is the loan amount (the home price minus your down payment), r is the monthly interest rate (the annual rate divided by 100, then divided by 12), n is the total number of monthly payments (the term in years multiplied by 12), and M is the monthly principal-and-interest payment. The calculator then adds your property tax divided by 12, your home insurance divided by 12, and any monthly HOA fee to give the total monthly payment.
The estimate assumes a fixed interest rate for the whole term, with payments made monthly. Property tax and insurance are spread evenly across the year, the way a lender’s escrow account handles them. It does not include private mortgage insurance (PMI), closing costs, or changes in tax and insurance bills over time, so treat the result as a solid planning estimate rather than a lender’s quote — your actual offer may differ.
How to Use This Calculator
- Enter the full purchase price of the home.
- Enter your down payment — the cash you plan to pay up front.
- Choose the loan term in years (30 and 15 are the most common) and type in the annual interest rate.
- Add the yearly property tax and yearly home insurance if you know them, plus any monthly HOA fee.
- Press Calculate and review the monthly principal and interest, the total monthly payment, the total interest, and the total cost of the home.
Example
For a $400,000 home with an $80,000 down payment, the loan amount is $320,000. Over 30 years at 6.5%, the monthly principal-and-interest payment is $2,022.62. Adding property tax of $4,800 a year ($400 a month) and insurance of $1,800 a year ($150 a month) brings the total monthly payment to $2,572.62. Across the 30 years you would pay $408,142.36 in interest, and the full cost of the purchase — down payment, loan payments, tax, and insurance — comes to $1,006,142.36.
As a comparison, the same $320,000 loan at 5.5% instead of 6.5% drops the principal-and-interest payment to $1,816.92 a month and cuts the total interest to $334,092.93 — roughly $74,000 saved from a single percentage point. A 15-year term at 6.5% raises the payment to $2,787.54 a month but slashes total interest to $181,757.84, less than half the 30-year figure.
What Affects the Result
- Down payment — every extra dollar down is a dollar you do not borrow, so it lowers both the payment and the lifetime interest.
- Interest rate — even half a percentage point changes the total interest by tens of thousands on a long loan, as the example above shows.
- Loan term — shorter terms mean higher payments but far less interest overall.
- Property tax and insurance — these vary widely by location and can add several hundred dollars a month; check local figures rather than guessing.
- Practical tip — run the numbers for two or three price points before you shop, so you know the payment range you are comfortable with before you fall for a particular house.
One more scenario is worth testing before you decide on a term: the middle ground. The same $320,000 loan over 20 years at 6.5% costs $2,385.83 a month in principal and interest — about $363 more than the 30-year payment, but with total interest of $252,600.17, roughly $155,000 less than the 30-year loan. Many buyers fixate on the choice between 15 and 30 years and never run the 20-year option, yet it often lands in a genuinely useful place: a payment that is meaningfully higher without being punishing, and an interest saving large enough to matter. Whatever term you lean towards, also remember that tax and insurance amounts in the calculator are today’s figures; lenders re-estimate escrow most years, so your real monthly payment will drift a little over time even though the loan part never changes.
Mortgage Calculator FAQs
Does this calculator include property tax and insurance?
Yes, if you enter them. Add the yearly property tax and yearly home insurance amounts and the calculator spreads each across 12 months and includes them in the total monthly payment, alongside any HOA fee you enter.
How much down payment do I need?
That depends on your lender and loan type. This calculator simply subtracts whatever down payment you enter from the home price. A larger down payment always lowers the amount borrowed, the monthly payment, and the total interest.
Why is the total interest so high on a 30-year mortgage?
Because interest is charged on a large balance for a long time. On a $320,000 loan at 6.5%, total interest over 30 years actually exceeds the amount borrowed. A shorter term or a lower rate reduces it dramatically.
Is the result the same as what a lender will quote me?
Not exactly. Real quotes can include PMI, closing costs, lender fees, and escrow adjustments that this estimate does not model. Use the result for planning and comparison, then confirm exact figures with your lender.
What happens if I leave the tax and insurance fields at zero?
The calculator then shows only the principal-and-interest payment and totals based on the loan itself. That is useful for comparing loans, but it understates the true monthly cost of owning the home.
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