Your monthly payment on a $400,000 house runs $2,100 to $2,900 depending on your down payment, interest rate, and loan term
The payment itself comes from three things: principal (the amount you borrowed), interest (what the lender charges), and property taxes plus insurance bundled into what's called PITI. A 30-year loan at 7% interest with 20% down ($80,000) costs roughly $2,660 per month in principal and interest alone. Add property taxes and homeowners insurance—which vary wildly by location—and you're looking at $3,200 to $3,800 total. A 15-year loan at the same rate costs about $3,700 monthly before taxes and insurance.
The number that matters most is your interest rate, because it compounds over the life of the loan. The difference between 6% and 8% on a $320,000 loan (after 20% down) is roughly $400 per month. Your down payment size matters too: put down 10% instead of 20% and you'll pay PMI (private mortgage insurance), adding $150 to $300 monthly until you hit 20% equity.
Key Takeaways
- Principal and interest on a $400,000 house with 20% down and a 7% rate over 30 years is approximately $2,660 monthly; add taxes and insurance to reach your true payment.
- Interest rates move the needle more than any other factor—a 1% difference changes your monthly payment by roughly $200 to $250.
- Putting down less than 20% triggers PMI, which adds $150 to $300 per month and stays until you own 20% of the home.
- Property taxes and homeowners insurance vary by state and county, so your actual total payment depends heavily on location.
- A 15-year loan costs roughly 40% more per month than a 30-year loan but saves you tens of thousands in interest over time.
How the payment breaks down: principal, interest, taxes, and insurance
Your mortgage payment has four parts, though lenders often bundle the last two. Principal is the portion that goes toward owning the house—it starts small and grows over time. Interest is what the lender charges; it starts large and shrinks as your balance falls. In the first payment on a $320,000 loan at 7%, you might pay $1,867 in interest and only $793 in principal. By payment 300, that flips.
Property taxes are set by your county and assessed annually, then divided into your monthly payment. A house worth $400,000 in a 1% tax area costs $333 per month; in a 2% area, $667. Homeowners insurance protects the lender's stake in the house and typically runs $100 to $200 monthly, though it can be higher in areas prone to hurricanes, earthquakes, or wildfires.
Many lenders require you to pay taxes and insurance through an escrow account—you send one check that includes all four pieces, and the lender pays the tax bill and insurance premium on your behalf. This protects the lender but also means your payment can jump if taxes rise or insurance rates climb.
How down payment size changes what you owe each month
A larger down payment shrinks your loan and your monthly payment. Here's the real math on a $400,000 house at 7% over 30 years:
| Down Payment | Loan Amount | Principal + Interest | PMI (if under 20%) | Total Before Taxes/Insurance |
|---|---|---|---|---|
| 10% ($40,000) | $360,000 | $2,394 | $200–$300 | $2,594–$2,694 |
| 15% ($60,000) | $340,000 | $2,265 | $150–$200 | $2,415–$2,465 |
| 20% ($80,000) | $320,000 | $2,135 | None | $2,135 |
| 25% ($100,000) | $300,000 | $1,996 | None | $1,996 |
PMI disappears once you own 20% of the home—either through down payment or by paying down the loan. You can request removal once you hit that threshold, though some lenders remove it automatically. Until then, it's a pure cost with no equity benefit.
Interest rates: the biggest lever on your monthly payment
A 1% swing in interest rate changes your monthly payment by roughly $200 to $250 on a $320,000 loan. At 6%, principal and interest run $2,316 monthly. At 7%, that's $2,516. At 8%, it's $2,721. Over 30 years, the difference between 6% and 8% totals more than $73,000 in extra interest paid.
Your rate depends on several things you can control and several you cannot. You cannot control the broader market—rates move with the Federal Reserve's decisions and economic conditions. You can control your credit score (higher scores get lower rates), your debt-to-income ratio (lower is better), your down payment size (larger down payments sometimes earn rate discounts), and your loan term (15-year loans often carry lower rates than 30-year loans, though the monthly payment is higher).
Shopping around matters. Different lenders quote different rates, and a 0.25% difference is worth hundreds of dollars over the life of the loan. Get quotes from at least three lenders before committing.
30-year versus 15-year loans: the payment and interest trade-off
A 30-year loan spreads payments over twice as long, so each payment is smaller but you pay far more interest overall. On a $320,000 loan at 7%, a 30-year payment is $2,135 monthly; a 15-year payment is $3,005. That's $870 more per month, but you own the house free and clear 15 years sooner and pay roughly $250,000 less in total interest.
The 30-year loan makes sense if you want lower monthly payments or if you have other high-interest debt to pay down first. The 15-year loan makes sense if you can afford the payment and want to minimize total interest and build equity faster. Some people split the difference: take a 30-year loan but make extra principal payments when cash flow allows, giving them flexibility without locking in the higher 15-year payment.
Property taxes and insurance vary by location—sometimes dramatically
A $400,000 house in New Jersey might carry $8,000 per year in property taxes; the same house in Alabama might carry $2,400. That's a $467 monthly difference before you even account for insurance. Homeowners insurance in Florida or California (hurricane and earthquake zones) can run $200 to $400 monthly; in low-risk areas, $80 to $120 is common.
These costs are not negotiable the way interest rates are. You pay what your county and insurer charge. But they matter enormously to your total payment, so factor them into your decision about where to buy. A house that looks affordable at 7% interest might strain your budget once you add the local tax bill.
What happens to your payment if rates or taxes change
Your principal and interest payment never changes on a fixed-rate mortgage—that's locked in for 30 years. But property taxes and insurance can rise, and when they do, your escrow payment rises with them. If your county reassesses your home's value upward or raises the tax rate, you'll see that reflected in your next escrow analysis, usually once per year. Insurance companies can also raise rates, and they often do after major storms or if claims rise in your area.
Some lenders send you an escrow analysis statement showing what your taxes and insurance are projected to be. If the number surprises you, ask the lender to walk through the math. You can also shop for new insurance annually—rates vary between companies, and switching can save $30 to $100 per month.
Frequently Asked Questions
Can I get a mortgage payment estimate before I apply?
Yes. Use an online mortgage calculator and plug in the loan amount, your estimated interest rate, and your loan term. The result won't include property taxes or insurance because those vary by location, but it gives you the principal-and-interest piece. Call your county assessor's office for the tax rate, and get insurance quotes from at least two companies to see what coverage costs in your area.
What if I can't afford the full payment?
You have a few options: buy a less expensive house, put down a larger down payment to shrink the loan, look for a lower interest rate by improving your credit score or shopping lenders, or consider a co-borrower with income to add to yours. Some lenders also offer graduated-payment mortgages where your payment starts lower and rises over time, though you pay more interest overall.
Does my payment include property taxes and insurance?
Only if your lender requires an escrow account, which most do if you put down less than 20%. If you put down 20% or more, you may be able to pay taxes and insurance separately. Ask your lender before closing—it affects your total monthly obligation.
What if my interest rate is higher than I expected?
Rates change daily based on market conditions and your personal profile. If you lock a rate and it drops before closing, you cannot go back—the lock protects you from increases, not decreases. If you haven't locked yet, shop multiple lenders; a 0.25% difference is worth hundreds of dollars per month. After closing, you can refinance if rates drop significantly, though you'll pay closing costs again.
How much should I budget for property taxes and insurance?
Call your county assessor for the tax rate and multiply it by the home's value. For insurance, get quotes from at least two companies—rates vary widely. Add both to your principal-and-interest payment to see your true monthly cost. Many people underestimate this piece and end up surprised at closing.