The monthly payment depends on your interest rate and loan term

On a $300,000 mortgage, your monthly payment (principal and interest only) ranges from roughly $1,432 to $2,864, depending on whether you lock in a 7% rate for 30 years or a 4% rate for 15 years. The longer your loan term, the lower your monthly payment—but you pay more interest overall. The higher your interest rate, the higher your payment every month.

This is the payment to your lender alone. Your actual monthly bill also includes property taxes, homeowners insurance, and possibly mortgage insurance (PMI), which can add $400 to $1,200 or more depending on your location, down payment, and home value. Lenders often bundle these into a single payment called PITI (principal, interest, taxes, insurance).

The numbers below show principal and interest only. Use them to understand how rate and term move the needle, then add your local costs to get the real figure you'll owe.

Key Takeaways

  • A $300,000 mortgage at 6% interest costs about $1,799 per month over 30 years—principal and interest only.
  • Dropping the rate to 4% cuts that to $1,432 per month; raising it to 8% pushes it to $2,201.
  • Shortening the term to 15 years raises your monthly payment but cuts total interest paid by more than half.
  • Property taxes, insurance, and PMI (if your down payment was less than 20%) add significantly to your monthly bill and vary by location and loan type.
  • Your actual payment is locked in at closing, so rate and term matter far more than market changes later.

How rate and term change your payment

Interest rate is the single biggest lever on your monthly payment. A 1% difference in rate changes your payment by roughly $250 to $300 per month on a $300,000 loan. At 4%, you pay $1,432 monthly over 30 years. At 5%, it jumps to $1,610. At 6%, it's $1,799. At 7%, $1,996. At 8%, $2,201.

Loan term (how many years you have to repay) works the opposite way. A 15-year mortgage has a higher monthly payment but costs far less in total interest. Over 30 years at 6%, you pay roughly $647,500 total. Over 15 years at the same rate, you pay roughly $423,600 total—saving you over $220,000, but your monthly payment jumps from $1,799 to $2,197.

Most borrowers choose 30 years because the lower payment fits their budget. Some choose 15 years if they can afford it and want to own the home free and clear sooner. A few choose 20 years as a middle ground, though fewer lenders offer this term.

What gets added to your principal and interest payment

Property taxes vary wildly by state and county. In low-tax states like Louisiana or Alabama, you might pay $150 to $300 per month on a $300,000 home. In high-tax states like New Jersey or Illinois, you could pay $600 to $1,000 or more. Your lender estimates this at closing and includes it in your monthly payment.

Homeowners insurance typically runs $100 to $300 per month depending on the home's age, location, and risk (flood, hurricane, wildfire). Lenders require this and collect it monthly, then pay your insurer on your behalf.

Mortgage insurance (PMI) is required if your down payment was less than 20%. On a $300,000 home, that means you put down less than $60,000. PMI costs roughly 0.5% to 1.5% of the loan amount per year, paid monthly. On a $240,000 loan (20% down), PMI might run $100 to $300 per month. You can remove it once you've paid down the principal to 80% of the home's value, though this takes years on a 30-year loan.

Some loans (FHA loans, VA loans, USDA loans) have different insurance structures. FHA loans charge an upfront mortgage insurance premium (1.75% of the loan, added to what you borrow) plus an annual premium paid monthly. VA and USDA loans may charge a one-time funding fee instead.

How your down payment affects the loan amount

The $300,000 figure might be the home's purchase price, but your loan amount depends on how much you put down. If you put down 20% ($60,000), you borrow $240,000. If you put down 10% ($30,000), you borrow $270,000. If you put down 3% ($9,000), you borrow $291,000.

A smaller down payment means a larger loan, a higher monthly payment, and PMI added to your bill. A larger down payment means a smaller loan and no PMI—but you need the cash upfront. Most first-time buyers put down 3% to 10%. Repeat buyers or those with savings often put down 15% to 20%.

Down payment also affects the interest rate you're offered. Lenders typically offer better rates to borrowers with 20% down than to those with 5% down, because the lender's risk is lower. The difference can be 0.25% to 0.75%, which translates to $75 to $225 per month on a $300,000 loan.

Fixed vs. adjustable rates and how they affect your payment

A fixed-rate mortgage locks in your interest rate for the entire loan term. Your principal and interest payment never changes. This is the most common choice and the easiest to budget for. If rates rise after you close, your payment stays the same.

An adjustable-rate mortgage (ARM) starts with a lower rate (often 0.5% to 1% lower than fixed) for a set period—usually 3, 5, 7, or 10 years. After that, the rate adjusts annually or semi-annually based on market conditions, and your payment rises or falls with it. ARMs are riskier because your payment can jump significantly after the fixed period ends. A 5/1 ARM, for example, has a fixed rate for 5 years, then adjusts annually after that.

Most borrowers choose fixed-rate mortgages because the payment is predictable. ARMs make sense only if you plan to sell or refinance before the rate adjusts, or if you're confident rates will stay low.

How to estimate your total monthly housing cost

Start with your principal and interest payment using the rate and term you're offered. Add your estimated property tax (your real estate agent or lender can provide this). Add homeowners insurance (get quotes from insurers). If your down payment is less than 20%, add PMI. If you have an HOA, add that too.

Example: $300,000 home, 10% down ($30,000), 6% rate, 30 years. Loan amount: $270,000. Principal and interest: $1,619. Property tax (estimate): $400. Insurance: $150. PMI: $200. Total: $2,369 per month.

Lenders use a debt-to-income ratio to decide how much to lend you. Most want your total housing payment (PITI plus PMI) to be no more than 28% of your gross monthly income. If you earn $6,000 per month, lenders typically cap your housing payment at $1,680. This is why down payment size and interest rate matter so much—they directly control whether you can afford the home at all.

What changes your payment after you close

Your principal and interest payment is locked in and never changes on a fixed-rate mortgage. But your property taxes can rise if your county reassesses the home's value, and your insurance can increase if claims rise in your area or your insurer raises rates. These changes are outside your control but will increase your monthly bill over time.

PMI can be removed once you reach 20% equity in the home (you've paid down the principal to 80% of the original purchase price). On a 30-year loan, this typically takes 10 to 15 years, depending on your rate and how much you pay down each month. Some borrowers refinance to a new loan with a larger down payment to drop PMI faster.

If interest rates fall significantly after you close, you can refinance to a new loan at the lower rate. This involves closing costs (typically 2% to 5% of the loan amount), so refinancing only makes sense if you plan to stay in the home long enough to recoup those costs through lower payments.

Frequently Asked Questions

What's the difference between the payment I see online and what my lender quotes me?

Online calculators usually show principal and interest only. Your lender's quote includes property taxes, insurance, and PMI, which vary by location and loan type. The lender's number is closer to what you'll actually pay each month. Always ask your lender for a Loan Estimate, which breaks down all costs.

Can I pay off my mortgage faster without refinancing?

Yes. You can make extra payments toward principal at any time without penalty on most mortgages. Paying an extra $200 per month cuts years off a 30-year loan and saves thousands in interest. Ask your lender whether extra payments go to principal or are held in escrow.

What happens to my payment if I get an ARM and rates spike?

Your payment can jump hundreds of dollars per month when the fixed period ends and the rate adjusts. A 5/1 ARM at 4% that adjusts to 7% could raise your payment by $400 to $600 monthly. This is why ARMs are risky unless you plan to refinance or sell before adjustment.

Does my credit score affect my monthly payment?

No, your credit score doesn't change the payment itself. But it affects the interest rate you're offered. A score of 760+ might get you 5.5%, while a score of 620 might get you 6.5% or higher. That 1% difference costs roughly $250 per month on a $300,000 loan.

What if I want to put down more than 20%?

You can put down as much as you want. A larger down payment lowers your loan amount, your monthly payment, and eliminates PMI. It also often qualifies you for a better interest rate. The tradeoff is that you need more cash upfront and have less liquidity after closing.