What goes into your monthly payment
Your monthly mortgage payment covers four things: principal (the amount you borrowed), interest (what the lender charges), property taxes, and homeowners insurance. Lenders call this PITI. The principal and interest portions stay the same for the life of a fixed-rate loan, but property taxes and insurance can change year to year, so your total payment may shift even if your loan terms don't.
The principal and interest are locked in on the day you close. If you borrowed $300,000 at 6.5% over 30 years, that piece of your payment will never change. Property taxes depend on your county's assessment and tax rate, and insurance depends on your home's value and your insurer's rates—both of these can go up or down.
If you have an escrow account, your lender collects taxes and insurance as part of your monthly payment and pays them on your behalf. If you don't, you pay the lender only for principal and interest, and you send property tax and insurance payments directly to the county and your insurance company.
Key Takeaways
- Your monthly payment includes principal, interest, property taxes, and insurance—only the first two are fixed on a fixed-rate loan.
- You can calculate principal and interest using an online mortgage calculator, a spreadsheet formula, or by hand if you know your loan amount, interest rate, and term.
- Property taxes and insurance are separate line items that vary by location and change over time, so get quotes from your county assessor and insurance agent.
- An escrow account bundles taxes and insurance into one monthly payment; without it, you pay the lender only for principal and interest and handle taxes and insurance separately.
- Your actual payment may differ from the calculation if your loan has an adjustable rate, includes mortgage insurance (PMI), or if you made a down payment smaller than 20 percent.
Using an online calculator
The fastest way to find your monthly payment is an online mortgage calculator. You enter your loan amount, interest rate, and loan term (usually 15, 20, or 30 years), and the calculator returns your principal and interest payment in seconds. Most calculators also let you add property taxes and insurance estimates, so you see your full PITI payment.
Bankrate, NerdWallet, and the Consumer Financial Protection Bureau all host free calculators that require no sign-up. Enter the numbers from your loan estimate or closing disclosure—the document your lender gave you before you closed. If you're shopping for a mortgage before you've locked in a rate, use current rates in your area as a starting point.
The calculator gives you the payment for a fixed-rate loan. If your loan is adjustable-rate (ARM), the payment shown is only for the initial fixed period; it will change when the rate adjusts. The calculator usually notes this, but read the fine print to be sure.
The formula if you want to calculate by hand
If you prefer to work it out yourself, the formula for monthly principal and interest is:
M = P × [r(1 + r)^n] / [(1 + r)^n − 1]
Where M is your monthly payment, P is the loan amount, r is your monthly interest rate (annual rate divided by 12), and n is the total number of payments (years times 12).
Example: You borrow $300,000 at 6.5% annual interest over 30 years. Your monthly rate is 0.065 ÷ 12 = 0.00542. Your total payments are 30 × 12 = 360. Plug those in and you get roughly $1,896 per month for principal and interest alone.
Most people use a spreadsheet (Excel, Google Sheets) to avoid the arithmetic. Both have a built-in PMT function that does this calculation for you. Type =PMT(rate, nper, pv) where rate is your monthly interest rate, nper is the number of payments, and pv is the loan amount as a negative number. The result is your monthly principal and interest payment.
Adding property taxes and insurance to the total
Once you have your principal and interest, you need to add property taxes and homeowners insurance. These vary widely by location and home value, so there is no single number.
For property taxes, contact your county assessor's office or check your property tax bill if you already own the home. The bill shows your annual tax; divide by 12 to get the monthly amount. If you're buying, the seller's most recent tax bill gives you a baseline, though your assessment may differ.
For homeowners insurance, get quotes from at least two insurers. The quote will be an annual premium; divide by 12 for the monthly cost. If you're buying and putting down less than 20 percent, you'll also pay private mortgage insurance (PMI), which protects the lender if you default. Your lender will quote this as a monthly amount or as a percentage of your loan.
Add principal + interest + (property taxes ÷ 12) + (insurance ÷ 12) + PMI (if applicable) to get your full monthly payment. This is what you'll see on your mortgage statement each month, though the property tax and insurance portions may shift if rates or assessments change.
Why your actual payment might differ from the calculation
A calculator gives you the payment for a standard fixed-rate loan with no surprises. Real mortgages often have wrinkles that change the number.
If you have an adjustable-rate mortgage (ARM), your interest rate is fixed for an initial period (often 3, 5, 7, or 10 years), then adjusts annually or semi-annually based on a market index. Your payment will stay the same during the fixed period, then jump or drop when the rate changes. A calculator can show you the initial payment, but not the future one.
If your down payment was less than 20 percent, you're paying PMI. This is an extra monthly cost that disappears once you've paid down the loan enough or your home value rises enough that you own 20 percent equity. Your lender will tell you when you can stop paying it, but the date depends on your loan terms and home value trends.
If you're in an escrow account, your lender may adjust your monthly payment once a year if property taxes or insurance rates change. You might also owe an escrow shortage (extra money) or get an escrow surplus (a refund) if the lender overestimated or underestimated those costs.
Spreadsheet templates and loan estimate documents
Your lender is required to give you a Loan Estimate within three business days of your application. This document shows your estimated monthly payment, broken down by principal, interest, taxes, insurance, and PMI. It's the most accurate number you'll get before closing, because it's based on your actual loan terms and your specific property.
At closing, you receive a Closing Disclosure, which shows your final loan terms and your actual monthly payment. This is the number that appears on your first mortgage statement.
If you want to build your own spreadsheet to track how your payment breaks down over time, use the PMT function for principal and interest, then add fixed cells for taxes and insurance. As you make payments, the principal portion grows and the interest portion shrinks, but the total stays the same (on a fixed-rate loan). A spreadsheet makes this visible and helps you understand where your money goes each month.
Frequently Asked Questions
Does the monthly payment include property taxes and insurance?
Only if you have an escrow account. With escrow, your lender collects taxes and insurance as part of your monthly payment and pays them for you. Without escrow, you pay the lender only for principal and interest, and you handle taxes and insurance separately. Your lender will tell you at closing whether escrow is required or optional.
What if my interest rate is adjustable?
During the fixed-rate period, your payment stays the same. Once the rate adjusts, your payment changes. A calculator shows only the initial payment. Ask your lender for an amortization schedule that shows what your payment could be after the rate adjusts, based on different rate scenarios.
Can I pay off my mortgage faster by increasing my monthly payment?
Yes. Any extra money you send goes toward principal, which shortens the loan and saves you interest. Some lenders allow biweekly payments (26 per year instead of 12 monthly), which also accelerates payoff. Check your loan documents to see if there are prepayment penalties—most modern mortgages have none.
How much does PMI cost?
PMI typically runs 0.5 to 1.5 percent of your loan amount per year, depending on your down payment and credit score. A lender will quote your specific PMI cost as part of your Loan Estimate. Once you reach 20 percent equity, you can request to have it removed.
What if I want to know my payment before I have a loan offer?
Use an online calculator with current mortgage rates in your area, your estimated down payment, and your target loan amount. This gives you a ballpark figure for budgeting. Your actual payment will differ once you lock in a rate and get a formal quote from a lender.