What goes into your monthly mortgage payment
Your mortgage payment has four parts, often called PITI: principal, interest, taxes, and insurance. Principal and interest are set by your loan amount and interest rate. Property taxes and homeowners insurance change based on where you live and what your home is worth. Most lenders combine all four into one monthly bill, though some let you pay taxes and insurance separately.
The principal is the amount you borrowed. Interest is what the lender charges you to borrow it — expressed as an annual percentage rate, or APR. On a 30-year loan, you pay far more in interest than principal in the early years. As time passes, more of each payment goes toward principal. Taxes and insurance are usually held in an escrow account — the lender collects a portion each month and pays the bills when they come due.
If you put down less than 20 percent, your payment also includes PMI (private mortgage insurance), which protects the lender if you stop paying. PMI typically costs 0.5 to 1.5 percent of your loan amount per year, added to your monthly bill. Once you reach 20 percent equity in the home, you can usually request to have it removed.
Key Takeaways
- Your monthly payment includes principal, interest, property taxes, homeowners insurance, and possibly PMI — most lenders combine these into one bill.
- You can estimate your payment using an online calculator with your loan amount, interest rate, and loan term, or by using the standard mortgage formula.
- Property taxes and insurance estimates vary widely by location and home value, so contact your local assessor and insurance agent for accurate figures.
- Your actual payment may be higher than the principal-and-interest calculation because it includes taxes, insurance, and possibly PMI.
- Lenders provide a Loan Estimate within three business days of your process, showing your exact projected payment before you commit.
The basic formula for principal and interest
If you want to calculate just the principal and interest portion, the standard formula 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). For a $300,000 loan at 6.5 percent over 30 years, this formula gives you roughly $1,896 per month in principal and interest alone.
Most people do not calculate this by hand. An online mortgage calculator — available from any major lender, Bankrate, or the Consumer Financial Protection Bureau — does the math when ready. You enter your loan amount, interest rate, and loan term (usually 15, 20, or 30 years), and the calculator shows your principal-and-interest payment in seconds.
Adding property taxes to the calculation
Property taxes are assessed by your county or municipality and vary dramatically by location. A home worth $400,000 might have annual property taxes of $4,000 in one state and $12,000 in another. To estimate yours, contact your local assessor's office or search your county's property tax database online — most are public.
Once you know the annual tax amount, divide it by 12 to get the monthly portion. If your annual property tax is $6,000, you would add $500 per month to your payment. The lender collects this in escrow and pays the bill when it comes due, usually once or twice a year.
If you are buying a home, the seller's property tax bill for the current year is public record. Ask your real estate agent or the title company to pull it — that gives you a realistic starting point, though your assessed value (and therefore your tax) may change after you purchase.
Adding homeowners insurance to the calculation
Homeowners insurance protects the structure of your home and your belongings. Lenders require it as a condition of the loan. The cost depends on your home's age, location, construction type, and the coverage limits you choose. A newer home in a low-crime area might cost $800 per year to insure; an older home in a hurricane zone might cost $3,000 or more.
Get quotes from at least three insurance companies before you finalize your mortgage. Most will give you a quote over the phone or online in minutes. Once you have a quote, divide the annual premium by 12 and add that to your monthly payment. The lender will collect this amount in escrow along with your property taxes.
Insurance costs can increase year to year, so your lender may adjust your escrow payment annually. If your home is damaged or your neighborhood's risk profile changes, your premium can jump significantly. Budget for the possibility that your total payment will rise.
Accounting for PMI if your down payment is less than 20 percent
If you are putting down less than 20 percent, your lender will require PMI. The cost is usually quoted as an annual percentage of your loan amount — for example, 0.8 percent per year. On a $300,000 loan, that would be $2,400 per year, or $200 per month.
PMI rates depend on your credit score, the size of your down payment, and the type of loan. A borrower with a 750 credit score putting down 10 percent pays less than someone with a 650 score putting down 5 percent. Ask your lender for the exact PMI rate before you lock in your interest rate.
PMI is not permanent. Once you reach 20 percent equity in your home — either by paying down the principal or by your home appreciating in value — you can request removal. Some loans remove it automatically at that point; others require you to ask. Check your loan documents or call your lender to understand the exact trigger.
Using a mortgage calculator to put it all together
An online calculator that includes taxes, insurance, and PMI will give you a complete picture of your monthly payment. Enter your loan amount, interest rate, loan term, estimated annual property taxes, estimated annual insurance cost, and whether you need PMI. The calculator will show you the total monthly payment.
Most lenders' websites have calculators built in. Bankrate, NerdWallet, and the Consumer Financial Protection Bureau also offer free calculators that do not require you to enter your personal information. These are useful for comparing scenarios — what if you put down 15 percent instead of 10 percent, or chose a 15-year loan instead of 30 years.
Keep in mind that these are estimates. Your actual payment depends on the exact interest rate you lock in, the final assessed value of the home, and the insurance company's final quote. These numbers can shift between the time you calculate and the time you close.
What the Loan Estimate tells you
Once you submit a mortgage process, federal law requires your lender to send you a Loan Estimate within three business days. This document shows your projected monthly payment broken down by principal and interest, property taxes, insurance, PMI (if applicable), and any other fees. It also shows your total interest paid over the life of the loan and your annual percentage rate (APR), which includes fees.
The Loan Estimate is not a may provide — your final payment may differ slightly if property taxes or insurance change, or if you lock in a different interest rate. But it is the most accurate number you will see before closing. Compare Loan Estimates from multiple lenders side by side; the format is standardized, so you can see exactly where they differ.
If the numbers on the Loan Estimate surprise you, ask your lender to explain them. If property taxes seem too high, verify them with the assessor. If insurance seems too high, get your own quotes and provide them to the lender. You have the right to understand every line before you sign.
Frequently Asked Questions
Does my payment change after I lock in my interest rate?
Your principal-and-interest payment does not change once you lock in your rate. However, property taxes and insurance can increase over time, which means your total monthly payment can rise. Some lenders adjust your escrow payment annually if taxes or insurance costs go up.
What if I want to pay off my mortgage faster?
You can choose a shorter loan term — 15 years instead of 30 — which increases your monthly payment but cuts your total interest paid roughly in half. You can also make extra principal payments on your own schedule without changing your loan term. Check your loan documents to confirm there is no prepayment penalty.
How much should I budget for property taxes and insurance if I do not know them yet?
Ask your real estate agent or the title company for the seller's current property tax bill — that is public record and gives you a baseline. For insurance, get quotes from at least three companies. If you are in the early stages and do not have a specific home yet, use national averages: roughly 1 percent of home value annually for property taxes and 0.5 to 1 percent for insurance, though these vary widely by location.
Can I remove PMI before I reach 20 percent equity?
Some loans allow you to request PMI removal once you reach 20 percent equity through a combination of payments and home appreciation. Others require you to wait until you automatically reach that threshold. A few loans let you refinance to remove PMI earlier. Check your loan documents or call your lender to understand your specific options.
What is the difference between my interest rate and my APR?
Your interest rate is what you pay to borrow the money. Your APR includes the interest rate plus lender fees, expressed as an annual percentage. The APR is always higher than the interest rate and gives you a more complete picture of the true cost of borrowing. Use APR when comparing loans from different lenders.