Understanding Mortgage Rates: How They Are Set and How to Get the Lowest Rate

What Determines Your Mortgage Rate?

When shopping for a home, even a tiny difference in your mortgage interest rate can save or cost you tens of thousands of dollars over the life of the loan. But have you ever wondered how mortgage rates are set? Why do rates rise one week and fall the next? And why does one buyer get quoted a 6.2% rate while another is quoted 7.2% on the same day?

Mortgage rates are determined by a combination of macroeconomic market forces (which set the baseline rate for all loans) and personal financial factors (which determine the risk premium lenders add to your specific loan).

This guide explains how mortgage rates are set in the United States and provides actionable strategies to help you secure the lowest possible rate for your home purchase.

Macroeconomic Factors: The Baseline Rate

Contrary to popular belief, the Federal Reserve does not directly set mortgage rates. Instead, mortgage rates are set by investor demand in the secondary mortgage market, specifically for Mortgage-Backed Securities (MBS).

Here are the primary macroeconomic forces that drive mortgage rates:

The 10-Year Treasury Yield: Mortgage rates track the yield of the 10-year US Treasury bond very closely. Because mortgages are long-term loans (which are typically prepaid or refinanced within 10 years), investors compare mortgage-backed securities to 10-year government bonds. When Treasury yields rise, mortgage rates rise; when yields fall, mortgage rates fall.
Inflation: Inflation is the biggest enemy of mortgage rates. Because a mortgage provides a fixed stream of payments over 30 years, inflation erodes the purchasing power of those future payments. When inflation rises, investors demand higher interest rates to compensate for this loss of purchasing power, causing mortgage rates to spike.
Federal Reserve Policy: While the Fed does not set mortgage rates, its monetary policy influences them. The Fed sets the federal funds rate—the short-term rate banks charge each other. To fight inflation, the Fed raises this rate, which increases borrowing costs across the economy and drives mortgage rates higher. The Fed’s decisions regarding its balance sheet (such as buying or selling mortgage-backed securities) also impact rates.
Economic Growth: A strong economy with high employment and rising consumer spending typically drives interest rates higher, as demand for loans increases. Conversely, during a recession, investors seek the safety of bonds, which drives bond yields and mortgage rates lower.

Personal Factors: Your Specific Rate

Once the baseline market rate is established, lenders evaluate your personal financial profile to determine your specific interest rate. The riskier you appear to the lender, the higher the interest rate they will charge. Lenders adjust rates based on Loan-Level Price Adjustments (LLPAs), which evaluate the following factors:

1. Credit Score

Your credit score is the single most important factor in determining your mortgage rate. A higher score indicates a history of responsible debt management, allowing you to qualify for the lowest rates. Lenders place borrowers into 20-point credit tiers. For example, a buyer with a 760 score will receive a lower interest rate quote than a buyer with a 679 score, even if all other factors are identical.

2. Loan-to-Value (LTV) Ratio / Down Payment

Your LTV ratio is the size of your mortgage compared to the value of the home. Making a larger down payment reduces your LTV and lowers the lender’s risk. A buyer making a 20% down payment (80% LTV) will almost always receive a lower interest rate quote than a buyer making a 3% down payment (97% LTV).

3. Occupancy Type

Lenders charge lower interest rates for primary residences (homes you live in) because borrowers are highly motivated to keep making payments to protect their shelter. Investment properties and second homes carry higher default risks, so lenders charge interest rates that are typically 0.5% to 1.0% higher.

4. Loan Type and Term

Shorter-term loans, like 15-year fixed mortgages, carry less risk for lenders and typically offer interest rates that are 0.5% to 0.75% lower than standard 30-year fixed mortgages. Adjustable-rate mortgages (ARMs) often start with lower introductory rates than fixed-rate mortgages, though they carry the risk of rate adjustments later.

Actionable Strategies to Secure the Lowest Mortgage Rate

If you are planning to buy a home, follow these steps to secure the lowest possible interest rate:

Improve Your Credit Score: Before applying for a mortgage, check your credit reports and resolve any errors. Pay down credit card balances to keep your credit utilization ratio below 10%, and avoid opening new credit cards or taking out auto loans in the months leading up to your purchase.
Save a Larger Down Payment: Increasing your down payment from 3% to 10% or 20% reduces your LTV ratio, which lowers your interest rate and reduces or eliminates your monthly PMI cost.
Shop Multiple Lenders: Mortgage rates can vary significantly from one lender to another. According to the Consumer Financial Protection Bureau (CFPB), shopping around with at least three lenders can save you thousands of dollars. Get quotes from retail banks, credit unions, and independent mortgage brokers.
Consider Paying Points: If you have extra cash at closing and plan to keep the home for a long time, you can pay discount points to buy down your interest rate. One point costs 1% of the loan amount and lowers the interest rate by approximately 0.25%, which can save you money over a 30-year term.

Use our Mortgage Calculator to check how a 0.25% or 0.5% difference in your interest rate affects your monthly payment and total lifetime interest costs, helping you evaluate whether paying points makes financial sense.