The payment depends on your interest rate, loan term, and down payment
On a $300,000 house, your monthly mortgage payment (principal and interest only) ranges from roughly $1,200 to $2,000, depending on three things: how much you put down, how long your loan is, and what interest rate you lock in. A 20% down payment ($60,000) on a 30-year loan at 7% interest runs about $1,330 per month. Put down 10% instead, and that same rate costs $1,490. At 6% interest with 20% down, it drops to $1,200. At 8%, it climbs to $1,466.
These numbers are principal and interest only — they do not include property taxes, homeowners insurance, HOA fees, or mortgage insurance, all of which add to your actual monthly bill. Your real payment is usually 20 to 35% higher than the base number.
Key Takeaways
- A $300,000 house with 20% down at 7% interest costs about $1,330 per month in principal and interest alone.
- Putting down less than 20% triggers mortgage insurance, which adds $150 to $400 per month depending on your down payment size.
- Property taxes and homeowners insurance typically add $300 to $600 per month, varying by location and home condition.
- Your total monthly housing payment is usually 25 to 35% higher than the base mortgage payment because of taxes, insurance, and fees.
- Interest rates change daily, so locking in a rate when you apply for a loan matters more than the national average.
How down payment size changes your payment
The more you put down, the less you borrow, and the lower your monthly payment. On a $300,000 house at 7% interest over 30 years:
| Down Payment | Loan Amount | Monthly Payment (P&I) | Mortgage Insurance |
|---|---|---|---|
| 20% ($60,000) | $240,000 | $1,330 | None |
| 15% ($45,000) | $255,000 | $1,414 | $200–$250 |
| 10% ($30,000) | $270,000 | $1,490 | $270–$350 |
| 5% ($15,000) | $285,000 | $1,566 | $350–$450 |
| 3% ($9,000) | $291,000 | $1,609 | $400–$500 |
Mortgage insurance (called PMI on conventional loans) is required when you put down less than 20%. It protects the lender if you stop paying, but you pay the premium. The smaller your down payment, the higher the insurance cost. PMI typically ranges from 0.5% to 1.5% of your loan amount per year, divided into your monthly payment.
How interest rate changes your payment
Interest rates move daily. A difference of 1% can cost you $100 to $150 per month on a $300,000 loan. Here is what the same $240,000 loan (20% down) costs at different rates over 30 years:
| Interest Rate | Monthly Payment (P&I) | Total Interest Paid Over 30 Years |
|---|---|---|
| 5.5% | $1,361 | $250,000 |
| 6.0% | $1,199 | $191,680 |
| 6.5% | $1,239 | $206,000 |
| 7.0% | $1,330 | $238,560 |
| 7.5% | $1,398 | $263,280 |
| 8.0% | $1,466 | $288,000 |
You lock in your rate when you submit a mortgage application, not when you make an offer on the house. Rates are set by the lender and move with market conditions. Shopping around with three to five lenders before you apply can save you thousands over the life of the loan.
What gets added to your base payment
Property taxes vary by county and state. In low-tax areas, they run 0.3% to 0.8% of home value per year. In high-tax areas, they can reach 1.5% or more. On a $300,000 house, that means anywhere from $75 to $375 per month. Your lender collects this in escrow — you pay it monthly as part of your mortgage bill, and the lender sends it to the county when it is due.
Homeowners insurance typically costs $800 to $1,500 per year, or $65 to $125 per month. Older homes, homes in flood zones, and homes in areas with high theft or weather risk cost more. Your lender requires insurance and collects the premium in escrow, just like taxes.
HOA fees (if the property is in a homeowners association) range from $100 to $500 per month and are not collected by the lender — you pay them separately to the HOA. Not all homes have HOA fees.
Your lender provides an estimate of taxes and insurance before you close, called a Loan Estimate. This document shows your base payment, insurance, taxes, and the total amount due each month. The estimate is not final — taxes and insurance can change after closing.
How loan term changes your payment
A 30-year loan spreads payments over three decades. A 15-year loan does the same in half the time, which means higher monthly payments but far less interest paid overall. On a $240,000 loan at 7% interest:
| Loan Term | Monthly Payment (P&I) | Total Interest Paid |
|---|---|---|
| 15 years | $1,796 | $83,280 |
| 20 years | $1,596 | $123,120 |
| 30 years | $1,330 | $238,560 |
Most buyers choose 30-year loans because the monthly payment is lower and leaves room in the budget for other expenses. A 15-year loan makes sense if you have stable income and want to own the house free and clear faster. Some buyers do a 30-year loan but pay extra toward principal each month, which shortens the loan without locking in the higher 15-year payment.
What changes after you close
Your payment can increase after closing if property taxes rise or your insurance premium goes up. Lenders reassess property taxes and insurance annually and adjust your escrow payment if needed. If your county raises the tax rate or your insurer raises premiums, your monthly bill goes up. This is normal and happens to most homeowners over time.
If you put down less than 20%, mortgage insurance eventually drops off. PMI is removed automatically once you reach 20% equity in the home (through a combination of payments and home value appreciation), or you can request removal once you hit that mark. This typically happens after 5 to 12 years, depending on your down payment and how fast you pay down the loan.
Frequently Asked Questions
Can I use an online calculator to figure out my exact payment?
Yes. Enter the home price, down payment amount, interest rate, and loan term into a mortgage calculator. The result shows principal and interest only. Add your estimated property taxes and insurance (your real estate agent or lender can provide county tax rates and insurance quotes) to get your true monthly cost.
What if interest rates drop after I lock in my rate?
You are stuck with the rate you locked in. However, you can refinance later if rates drop significantly — refinancing means taking out a new loan to pay off the old one. Refinancing has closing costs (typically 2 to 5% of the loan amount), so it only makes sense if the rate drop is large enough to offset those costs over the time you plan to stay in the home.
Does my credit score affect the interest rate I get?
Yes. Borrowers with credit scores above 740 typically get the lowest rates. Scores between 680 and 740 get slightly higher rates. Scores below 680 get noticeably higher rates or may not be approved at all. A 20-point difference in credit score can mean a 0.25% to 0.5% difference in your rate, which adds $50 to $100 per month on a $300,000 loan.
What if I want to pay off the mortgage early?
You can pay extra toward principal at any time without penalty on most mortgages. Paying an extra $100 or $200 per month shortens your loan by years and saves tens of thousands in interest. Ask your lender to confirm your loan has no prepayment penalty before you start making extra payments.
How much house can I actually afford?
Most lenders approve you for a loan if your total monthly housing payment (mortgage, taxes, insurance, HOA) does not exceed 28% of your gross monthly income. On a $300,000 house, that payment is typically $1,800 to $2,200, which means you need a gross monthly income of around $6,400 to $7,900 (or $77,000 to $95,000 per year). Your actual approval depends on your debt, income, and credit score.