How is a mortgage payment calculated?

Monthly principal and interest uses the standard amortization formula from loan amount, annual rate, and term in months. Optional property tax and insurance are divided by 12 and added to estimate a full monthly housing cost.

What is included in the estimated monthly total?

Principal, interest, and the optional tax and insurance you enter. PMI, HOA dues, and other escrow items are not included unless you add them into tax or insurance.

How much interest do I pay on a 30-year mortgage?

Total interest is the sum of all monthly PI payments minus the original loan amount. At typical rates, interest over 30 years can rival or exceed the amount you borrowed.

Should I pick a 15-year or 30-year mortgage?

A 15-year term usually means a higher monthly PI and far less total interest. A 30-year term lowers the payment and costs more interest over the life of the loan.

No. PMI, HOA, and other escrow items are not included unless you add them into tax or insurance.

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Mortgage Payment Calculator

Estimate monthly payment, total interest, and payoff for any home loan.

Home price ($)

Down payment ($)

Loan term (years)

Interest rate (%)

Property tax / year ($) optional

Insurance / year ($) optional

Monthly principal + interest

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Estimated monthly total

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Total interest

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Total paid

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Next step: test a rate cut on the Refinance Calculator or house fit on Affordability. We do not sell lender leads yet. As an Amazon Associate, DynDisc earns from qualifying purchases on Picks.

How this mortgage calculator works

Enter the home price, down payment, loan term, and interest rate. Optional annual property tax and homeowners insurance are divided by 12 and added to principal and interest (PI). The result is monthly PI, an estimated monthly total (PI + tax/12 + insurance/12), total interest over the full term, and total of all PI payments. Amortization is standard fixed-rate math — the same formula lenders use for the PI line on a quote.

Down payment shrinks the loan amount (price − down). A larger down payment lowers both the monthly PI and total interest. Term length is the other big lever: the same balance at the same rate costs far less interest on 15 years than on 30, but the monthly PI is higher.

PI vs PITI — what you actually write each month

Principal and interest is only the amortizing loan. PITI adds tax and insurance (and often escrow). Many first-time buyers compare PI quotes and then get surprised when escrow pushes the draft higher. Use the optional tax and insurance fields here so the “estimated monthly total” is closer to what hits your account.

Not included unless you fold them into tax or insurance: PMI (common under 20% down), HOA dues, flood insurance, and other escrow items. If your lender quotes PMI, add that monthly amount into insurance or tax so the total stays honest.

15-year vs 30-year and how to read total interest

On a 30-year loan at typical rates, total interest can rival or exceed the amount you borrowed. That is normal amortization, not a bug. A 15-year term usually means a higher monthly PI and a much smaller interest bill. Run both terms with the same price, down payment, and rate, then decide whether the payment jump is worth the interest cut.

If rates drop later, the refinance calculator is the break-even tool. If you want to attack principal without changing the rate, use the loan payoff calculator with an extra monthly payment. House fit (payment vs income) belongs on affordability.

How to use this page before you shop

Lock a payment range you can live with, then shop lenders inside that range — not the other way around. Re-run when the price, down payment, or quoted rate changes. Treat this as an educational estimate: real quotes include fees, credits, and underwriting that this page does not model.

FAQ

How is a mortgage payment calculated?: Monthly principal and interest uses the standard amortization formula from loan amount, annual rate, and term in months. Optional property tax and insurance are divided by 12 and added to estimate a full monthly housing cost.
What is included in the estimated monthly total?: Principal, interest, and the optional tax and insurance you enter. PMI, HOA dues, and other escrow items are not included unless you add them into tax or insurance.
How much interest do I pay on a 30-year mortgage?: Total interest is the sum of all monthly PI payments minus the original loan amount. At typical rates, interest over 30 years can rival or exceed the amount you borrowed.
Should I pick a 15-year or 30-year mortgage?: A 15-year term usually means a higher monthly PI and far less total interest. A 30-year term lowers the payment and costs more interest over the life of the loan. Run both here before you lock a term with a lender.
Is PMI included?: No. PMI, HOA, and other escrow items are not included unless you add them into tax or insurance.
Does a larger down payment always help?: Yes for PI and total interest: less borrowed means a smaller payment and less interest. It can also help you avoid PMI once you reach about 20% equity, which this calculator does not model separately.
When should I use the refinance calculator instead?: When you already have a mortgage and want to know whether a lower rate (and closing costs) beats staying. This page is for a new purchase payment; refinance break-even lives on the refinance calculator.