Banks use your credit score, down payment, loan term, and current market rates to set your interest rate

Your interest rate is not a number the bank pulls from a table. It is built from several pieces of information about you and the loan itself. A bank looks at how reliably you have paid debts in the past (your credit score), how much of your own money you are putting down, how long you want to borrow for, and what interest rates are trading at in the bond market that day. Each of these moves the rate up or down.

The rate you see advertised is a starting point, not your rate. Your actual rate depends on your specific situation. Two people applying on the same day can receive different rates because their credit histories, down payments, or loan structures are different. Understanding what moves the needle helps you see where you have control and where you do not.

Key Takeaways

  • Your credit score is the single largest factor a bank uses to price your loan, with scores below 620 often resulting in higher rates or loan denial.
  • A larger down payment lowers your rate because the bank's risk decreases — you have more of your own money at stake.
  • The loan term (15 years versus 30 years) affects your rate; shorter terms usually carry lower rates because the bank's risk window is smaller.
  • Market interest rates set the floor; your personal rate sits above that floor based on your credit and loan details.
  • Locking your rate freezes it for a set number of days, protecting you if rates rise before closing, but costing you if rates fall.

How your credit score moves your interest rate

Your credit score is the fastest way a bank estimates whether you will pay the loan back. Scores range from 300 to 850. A score of 740 or higher typically qualifies you for the best rates a bank is offering that day. A score between 620 and 739 will cost you more — sometimes a quarter of a percent higher, sometimes a full percent or more, depending on the lender and the loan size. Below 620, many banks will not lend to you at all, or will charge rates that make the loan unaffordable.

The score reflects your payment history (35 percent of the score), how much debt you are carrying relative to your credit limits (30 percent), the length of your credit history (15 percent), the mix of credit types you use (10 percent), and recent credit inquiries or new accounts (10 percent). A bank sees the score as a shorthand for risk. A person who has missed payments or carries high balances is statistically more likely to default, so the bank charges them more to offset that risk.

If your score is lower than you want, paying down existing debt and making on-time payments for several months before you apply can move it up. Checking your own credit report for errors is also worth doing — mistakes happen, and disputing them can raise your score without you having to change your behavior.

Why your down payment percentage affects the rate

The larger your down payment, the lower your rate. A 20 percent down payment typically gets you a better rate than a 10 percent down payment on the same house. A 5 percent down payment gets a worse rate still. The reason is simple: if you default, the bank has to foreclose and sell the house. If you put down 20 percent, the house has to drop 20 percent in value before the bank loses money. If you put down 5 percent, the house only has to drop 5 percent. The bank's risk is higher with a smaller down payment, so it charges you more.

Down payments below 20 percent also trigger private mortgage insurance (PMI), an extra monthly payment that protects the bank if you stop paying. PMI is not the same as your interest rate, but it is another cost that shrinks as your down payment grows. Some buyers focus only on the interest rate and miss that PMI can add hundreds of dollars a year to the total cost.

If you are putting down less than 20 percent, you have a choice: save longer to reach 20 percent and avoid PMI and a higher rate, or buy sooner with a smaller down payment and accept both. The math depends on how long you plan to stay in the house and what rates are doing.

How loan term (15 years versus 30 years) changes your rate

A 15-year mortgage almost always carries a lower interest rate than a 30-year mortgage, even when both are offered on the same day. The reason is time and risk. Over 15 years, there are fewer opportunities for you to lose your job, face a health crisis, or encounter other hardships that make you unable to pay. The bank's money is also back in its hands sooner, so it does not have to hold the risk as long. A 30-year loan exposes the bank to 15 additional years of uncertainty.

The rate difference is usually between 0.25 and 0.5 percent, though it varies by lender and market conditions. On a $300,000 loan, that difference can mean $50 to $100 more per month on a 30-year loan compared to a 15-year loan — but the 30-year payment is also lower because you are spreading the principal over more years. The choice between them is not just about the rate; it is about what monthly payment fits your budget.

What market interest rates are and why they move

The interest rates banks offer are tied to the bond market, particularly the yield on 10-year U.S. Treasury bonds and mortgage-backed securities. When those yields rise, mortgage rates rise. When they fall, mortgage rates fall. This happens because banks borrow money themselves to fund mortgages, and they price their loans based on what they have to pay to get that money.

Market rates move based on inflation, Federal Reserve policy, economic growth, and global events. You cannot control market rates, but you can see them. Most lenders publish their current rates online, and you can compare them across multiple banks. The rate you see advertised is usually the rate for a borrower with excellent credit and a 20 percent down payment. Your actual rate will be higher or lower depending on your specific profile.

Market rates change daily, sometimes multiple times a day. If you are shopping for a mortgage, you will see different rates quoted on different days. This is normal and expected.

How locking your rate works and when to do it

Once you find a lender and agree on a rate, you can lock that rate for a set number of days — typically 30, 45, or 60 days. Locking means the bank promises to give you that rate at closing, even if market rates rise in the meantime. If rates fall, you are stuck with the higher locked rate (though some lenders offer a "float down" option that lets you take a lower rate if one becomes available, usually for a fee).

The decision to lock depends on where you are in the process and what you think rates will do. If you are close to closing and rates have been rising, locking protects you. If you are early in the process and rates are falling, you might float (not lock) and hope they keep falling. The risk of floating is that rates could rise and you would have to accept a higher rate or walk away from the loan.

Locking has a cost, though it is usually built into the rate you are quoted rather than charged as a separate fee. A bank that offers a lower rate might require a shorter lock period or charge a fee to extend the lock. Ask your lender what the lock terms are and what happens if you need more time before closing.

How points and fees affect your effective interest rate

Some lenders offer you a choice: pay a lower interest rate and higher upfront fees (called points), or pay a higher interest rate and lower fees. One point equals 1 percent of the loan amount. On a $300,000 loan, one point is $3,000. Paying points upfront lowers your monthly payment and your total interest paid over the life of the loan, but it costs money at closing.

Whether points make sense depends on how long you plan to stay in the house. If you are selling or refinancing in five years, paying points might not pay for itself. If you are staying 15 years or longer, points usually save you money. Your lender can show you a comparison: if you pay $3,000 in points, how many months until your lower monthly payment makes up for that $3,000? If that break-even point is before you plan to leave, points are worth it.

Origination fees, appraisal fees, and title insurance are separate from points and are charged by most lenders. These are not negotiable in the same way points are, but you can shop around — different lenders charge different amounts for the same services.

Why different lenders quote different rates for the same loan

Banks have different costs, different risk appetites, and different business models. A large national bank might quote you one rate, a credit union another, and a mortgage broker a third. The differences are usually small — a tenth of a percent or two — but they add up over 30 years.

Some lenders make money primarily on interest; others make money on fees and points. A lender with lower fees might have a higher rate, and vice versa. Some lenders specialize in borrowers with lower credit scores and price accordingly. Others focus on borrowers with excellent credit and offer the best rates to that group.

Shopping around is the only way to know what you may have access to for. Most lenders will give you a rate quote without a hard credit inquiry, so you can compare three to five lenders without damaging your credit score. Once you are ready to move forward with one lender, they will do a hard inquiry and pull your full credit report.

Frequently Asked Questions

Can I negotiate my interest rate with a bank?

Not directly — the rate is based on your credit, down payment, loan term, and market conditions, not on haggling. But you can shop around, and you can ask a lender to match a competitor's rate. You can also ask about paying points to lower your rate, or accepting a higher rate to lower your upfront costs.

What is the difference between APR and interest rate?

The interest rate is what you pay on the loan balance. The APR (annual percentage rate) includes the interest rate plus fees and points, expressed as an annual rate. APR is usually higher than the interest rate and gives you a more complete picture of the true cost of borrowing.

If I have a low credit score, should I wait to buy a house?

It depends on your situation. Waiting six months to a year to improve your credit can save you tens of thousands of dollars in interest over a 30-year loan. But if you are renting and prices are rising, waiting might cost you more in the long run. Run the numbers with a lender to see what rate you would get now versus what you might get if you wait.

Does my interest rate change after I lock it?

No — once you lock, your rate is fixed for the lock period (usually 30 to 60 days). After closing, your rate is locked for the life of the loan unless you refinance. If you have an adjustable-rate mortgage (ARM), the rate can change after an initial fixed period, but that is a different product and you would know about it upfront.

Why did my rate quote change between pre-approval and closing?

If you did not lock your rate, it can move with market conditions. If you did lock it, the rate should not change unless you extended the lock period or changed the loan terms (loan amount, down payment, or term length). Ask your lender to explain any change in writing.