What Is a Mortgage Payment Made Of?
Your monthly mortgage payment typically has four components, often called PITI:
- Principal — the portion that reduces your loan balance
- Interest — the cost of borrowing money from the lender
- Taxes — your share of annual property taxes, collected monthly
- Insurance — homeowner's insurance, and PMI if your down payment is under 20%
When a lender gives you a "monthly payment estimate," they often quote only principal and interest. That number can be $300–600 lower than what you'll actually pay. Always ask for the full PITI estimate.
The Math Behind Principal and Interest
The P&I portion of your payment is calculated using a fixed formula called an amortization formula:
Your monthly P&I payment depends on three things: your loan amount, your interest rate, and your loan term. With a 30-year loan, you'll make 360 equal monthly payments. With a 15-year loan, 180 payments. The payment is structured so that you pay mostly interest in early years and mostly principal later — this is called amortization.
For example, on a $300,000 loan at 7% interest for 30 years, your monthly P&I payment would be approximately $1,996. In your first payment, about $1,750 goes to interest and only $246 goes to principal. By year 20, those numbers flip significantly.
How Property Taxes Are Added
Your lender collects property taxes monthly and holds them in an escrow account, then pays your local government when taxes are due. Most US counties charge between 0.5% and 2.5% of the home's value per year in property taxes.
To estimate your monthly property tax payment: take the home's assessed value, multiply by the local tax rate, and divide by 12. On a $350,000 home in a county with a 1.2% tax rate, that's $350 per month added to your payment.
You can look up your county's property tax rate on your county assessor's website before making an offer.
Homeowner's Insurance
Lenders require you to carry homeowner's insurance and will add it to your escrow payment. The national average for homeowner's insurance is around $1,200–1,800 per year, depending on your location, the home's value, and your coverage level. That translates to roughly $100–150 per month added to your mortgage payment.
Florida, Texas, and coastal states tend to have significantly higher insurance costs due to hurricane and flood risk. Always get an insurance quote before finalizing your budget.
Private Mortgage Insurance (PMI)
If your down payment is less than 20% of the purchase price, your lender will require PMI. This protects the lender — not you — in case you default. PMI typically costs 0.5%–1.5% of the loan amount per year.
On a $280,000 loan with a 1% PMI rate, you'd pay about $233 per month in PMI on top of everything else. The good news: once your home equity reaches 20%, you can request PMI removal.
A Real Example: Full Monthly Payment Breakdown
Let's say you're buying a $400,000 home with 10% down ($40,000), a 7% interest rate, 30-year term, in a county with 1.1% property taxes, and standard insurance:
- Loan amount: $360,000
- Principal & Interest: ~$2,395/month
- Property tax (1.1% / 12): ~$367/month
- Homeowner's insurance: ~$125/month
- PMI (0.8% / 12): ~$240/month
- Total monthly payment: ~$3,127/month
Compare that to the P&I-only quote of $2,395 — a difference of over $700. This is why it's critical to calculate the full payment, not just the base loan payment.
How Interest Rate Affects Your Payment
Interest rate has a bigger impact on your payment than most people realize. On a $350,000 loan:
- At 6.0%: ~$2,098/month P&I
- At 6.5%: ~$2,212/month P&I
- At 7.0%: ~$2,329/month P&I
- At 7.5%: ~$2,448/month P&I
A 1% difference in rate costs you about $230/month, or $82,800 over a 30-year loan. This is why shopping multiple lenders and comparing rates is one of the highest-value things you can do as a homebuyer.
Loan Term: 30 vs 15 Years
A 15-year mortgage will have a higher monthly payment than a 30-year mortgage on the same loan amount, but you'll pay dramatically less interest over the life of the loan. On a $300,000 loan at 6.5%:
- 30-year: ~$1,896/month, total interest paid: ~$382,000
- 15-year: ~$2,613/month, total interest paid: ~$170,000
You'd pay $717 more per month but save over $212,000 in interest. Whether that tradeoff makes sense depends on your income, other financial goals, and how long you plan to stay in the home.
Calculate Your Payment Instantly
You don't need to do all this math by hand. Our free Mortgage Calculator calculates your full monthly payment including taxes, insurance, and PMI — not just principal and interest. Enter your home price, down payment, interest rate, and local tax rate, and see a complete breakdown in seconds.
If you're still figuring out how much home you can afford, try our Affordability Calculator which works backward from your income and debts to tell you your maximum home price.
Key Takeaways
- Your full mortgage payment includes principal, interest, property taxes, insurance, and possibly PMI
- The P&I-only quote from lenders can be $300–600 lower than your real payment
- Interest rate has a major impact — shop multiple lenders
- PMI is required with less than 20% down and can add $100–300/month
- Always calculate the full PITI payment before deciding how much to offer