How to Calculate What Your Monthly House Payment Will Be
Your house payment comes from four parts: principal, interest, property taxes, and insurance
Your monthly payment is not just the loan amount divided by the number of months. It includes the interest the lender charges, the property taxes your county or municipality collects, and the homeowners insurance your lender requires. Together, these are often called PITI — principal, interest, taxes, and insurance. The principal and interest stay the same every month (on a fixed-rate loan). The taxes and insurance can change year to year, which means your total payment can shift even after you close.
The principal is the amount you borrowed. The interest is what the lender charges you to borrow it, expressed as an annual percentage rate. Property taxes depend on your home's assessed value and your local tax rate. Insurance protects the lender's investment if your home is damaged or destroyed. If you put down less than 20 percent, you will also pay PMI — private mortgage insurance — which protects the lender if you stop paying.
Key Takeaways
- Your monthly payment has four parts: principal and interest (which stay the same), plus property taxes and homeowners insurance (which can change each year).
- You can estimate your payment using your loan amount, interest rate, and loan term, but you need your local property tax rate and insurance quote to get the full picture.
- If you put down less than 20 percent, your payment will include PMI until you reach 20 percent equity or refinance.
- Property taxes and insurance can increase over time, so your payment may be higher in year five than it was in year one.
- Your lender will give you a Loan Estimate within three business days of your application, which shows your exact projected payment.
How to find the principal and interest portion
The principal and interest part of your payment is calculated using three numbers: the loan amount, the interest rate, and the loan term (usually 15, 20, or 30 years). Lenders use a standard formula to spread the principal and interest evenly across all your monthly payments. Early payments are mostly interest; later payments are mostly principal.
You can calculate this yourself using an online mortgage calculator — search "mortgage payment calculator" and enter your loan amount, interest rate, and term. Or you can ask your lender directly; they will give you this number as part of your Loan Estimate, a document they must send you within three business days of your application. The Loan Estimate shows your projected principal and interest payment, plus estimates for taxes, insurance, and PMI.
Do not rely on a calculator alone for major decisions. The calculator gives you an estimate. Your lender's Loan Estimate is the official projection based on your actual application and the terms they are offering you.
How property taxes affect your payment
Property taxes are set by your county or municipality and are based on your home's assessed value. The assessed value is not the same as the price you paid — it is determined by the assessor's office and can be lower or higher. Tax rates vary widely by location. In some counties, property tax is less than 0.5 percent of home value per year; in others, it is over 2 percent.
To estimate your property tax portion, you need two pieces of information: the assessed value of the home you are buying (your real estate agent or the county assessor's website can provide this) and your local property tax rate (your county assessor's office publishes this). Multiply the assessed value by the tax rate, then divide by 12 to get your monthly amount. Your lender will include an estimate on your Loan Estimate, but it may change after you close if the assessor updates the value.
Property taxes typically increase every few years as your home's assessed value rises or as your municipality raises the tax rate. This means your payment will go up even if your principal and interest stay the same.
How homeowners insurance changes your payment
Your lender requires you to carry homeowners insurance and will collect the premium from you each month as part of your payment. The lender then pays the insurance company directly. The cost depends on your home's location, age, construction, and the coverage level you choose. A home in a flood zone or an older home with outdated wiring will cost more to insure than a new home in a low-risk area.
Get insurance quotes before you make an offer or finalize your loan. You can contact insurance companies directly or use an independent agent who works with multiple insurers. When you get a quote, ask for the annual premium; divide by 12 to see what your monthly payment will include. Your lender will ask for a copy of your insurance binder (proof of coverage) before closing.
Insurance premiums increase over time, especially if you file a claim or if your insurer raises rates across your area. Budget for this increase when you think about affordability.
What PMI adds if you put down less than 20 percent
If your down payment is less than 20 percent of the home's purchase price, your lender will require PMI — private mortgage insurance. This protects the lender, not you. PMI typically costs between 0.5 and 1.5 percent of your loan amount per year, though the exact rate depends on your credit score, the size of your down payment, and your lender. A lower down payment or lower credit score means higher PMI.
PMI is added to your monthly payment. You can remove it once you reach 20 percent equity in your home — either by paying down the principal or by refinancing. Some lenders will automatically remove PMI once you hit 20 percent equity; others require you to request it. Ask your lender about their PMI removal policy before you close.
PMI is not permanent, but it can add $100 to $300 or more to your monthly payment depending on your loan size and credit profile. Factor this into your affordability calculation if you are putting down less than 20 percent.
How to read your Loan Estimate
Your lender must send you a Loan Estimate within three business days of your application. This is a standardized form that shows your projected monthly payment broken down by principal and interest, property taxes, homeowners insurance, PMI (if applicable), and HOA fees (if applicable). It also shows your total monthly payment and your total closing costs.
The Loan Estimate is an estimate, not a may provide. Property taxes and insurance can change between the estimate and closing. The principal and interest will not change if you lock in your interest rate and keep the same loan term and amount. Compare Loan Estimates from different lenders side by side — the form is the same at every lender, so you can see exactly where they differ.
Ask your lender to explain any line item you do not understand. If a number seems wrong — for example, if the property tax estimate is much higher than what you calculated — ask the lender to show you how they arrived at it. This is your chance to catch errors before you close.
How your payment can change after you close
Your principal and interest payment will not change if you have a fixed-rate mortgage. But your property taxes and insurance almost certainly will over time. Property taxes typically increase every few years as your home's assessed value rises or as your municipality raises rates. Homeowners insurance premiums increase when you file a claim, when your insurer raises rates in your area, or when you make changes to your home.
Your lender collects taxes and insurance in an escrow account — a separate account held in your name. Each month, your lender deposits your tax and insurance portions into this account. When taxes or insurance are due, the lender pays them from the account. If the account does not have enough money to cover the bill, your lender will increase your monthly payment. This is called an escrow adjustment.
You will receive a notice if your lender raises your payment due to an escrow adjustment. This is normal and expected. Budget for increases of 5 to 10 percent every few years, though the actual increase depends on your local tax and insurance markets.
Frequently Asked Questions
Can I get an exact payment before I close on the house?
Your Loan Estimate gives you a very close projection, but the exact payment depends on the final assessed value of the home and the exact insurance premium your lender locks in. These can shift slightly between the estimate and closing. After you close, your first payment notice will show your actual payment amount.
What if my property taxes or insurance are much higher than the estimate?
Contact your lender immediately. If the property tax estimate was wrong, ask the lender to recalculate based on the correct assessed value. If insurance is higher, you can shop for a different policy and provide the new quote to your lender. Your lender must use the actual insurance premium in your payment calculation.
Does my payment include utilities and maintenance?
No. Your mortgage payment covers only principal, interest, property taxes, homeowners insurance, and PMI (if applicable). You pay utilities, maintenance, repairs, and HOA fees separately. Budget for these costs in addition to your mortgage payment.
Can I pay extra toward principal to lower my payment?
Extra principal payments lower the amount you owe and reduce the total interest you pay over the life of the loan, but they do not lower your monthly payment amount. Your lender will continue to expect the same payment each month. Any extra you pay goes directly toward principal. Ask your lender about their policy on extra payments before you close.
What happens if I refinance?
Refinancing replaces your current loan with a new one, which means a new principal and interest payment. Your property taxes and insurance stay the same (they are not part of the refinance), but your new lender will set up a new escrow account and may estimate taxes and insurance differently. You will receive a new Loan Estimate for the refinance.