If you're buying a home or refinancing, the mortgage rate you lock in will shape your budget for years. A difference of half a percentage point on a $400,000 loan can change your monthly payment by well over $100. Understanding how mortgage rates are set — and how to compare offers — is one of the highest-value pieces of financial knowledge a homeowner can have.
This guide explains what drives mortgage rates, the difference between fixed and adjustable loans, why APR matters alongside the interest rate, and the practical steps that help borrowers get a better deal.
What Determines Mortgage Rates?
Mortgage rates are not set by any single entity. They are shaped by a mix of broad economic forces and your personal financial profile.
Economic forces
- Federal Reserve policy. The Fed sets the federal funds rate, which influences short-term borrowing costs across the economy. The Fed does not set mortgage rates directly, but its decisions move the bond market that mortgage pricing follows.
- The 10-year Treasury yield. Mortgage rates tend to track the yield on the 10-year Treasury note, because both compete for the same investor dollars. When Treasury yields rise, mortgage rates usually follow.
- Inflation expectations. Lenders demand higher yields when they expect inflation to erode the value of future payments, pushing mortgage rates up.
- Mortgage-backed securities demand. Most US mortgages are bundled into securities sold to investors, often through Fannie Mae and Freddie Mac. Strong investor demand for these securities pushes rates down.
Borrower-specific factors
- Credit score. Borrowers with higher scores typically qualify for lower rates. On a conventional loan, the gap between a 620 score and a 760 score can be substantial.
- Down payment. Putting down 20% or more usually avoids private mortgage insurance (PMI) and can earn a better rate.
- Loan type and term. A 30-year fixed loan generally carries a higher rate than a 15-year fixed loan, because the lender takes on more interest-rate risk over a longer period.
- Property type and occupancy. Primary residences typically get better pricing than investment properties or second homes.
Fixed vs. Adjustable-Rate Mortgages
The two main structures behave very differently over time.
Fixed-rate mortgages
The interest rate stays the same for the life of the loan, so your principal-and-interest payment never changes. A 30-year fixed mortgage is the most common choice in the US because it offers predictable payments. A 15-year fixed mortgage usually comes with a lower rate and builds equity faster, but the monthly payment is higher.
Adjustable-rate mortgages (ARMs)
An ARM starts with a fixed introductory period — often 5, 7, or 10 years — then adjusts periodically based on an index plus a margin. A 5/1 ARM, for example, is fixed for five years and then adjusts once per year. ARMs often start below fixed rates, which can make sense if you plan to sell or refinance before the first adjustment. After that, your payment can rise significantly, so read the caps carefully: most ARMs limit how much the rate can increase per adjustment and over the life of the loan.
Interest Rate vs. APR: Why Both Matter
The interest rate is the cost of borrowing the principal. The annual percentage rate (APR) is broader: it includes the interest rate plus most lender fees, points, and mortgage insurance, expressed as a yearly cost.
APR is useful for comparing offers with different fee structures, but it has limits. Because it spreads upfront costs across the full loan term, APR can understate the cost of a loan you plan to keep only a few years. A common approach is to compare both numbers, then weigh the total upfront cost against how long you expect to stay in the home.
Also watch for discount points — an upfront fee that buys a lower rate. One point equals 1% of the loan amount. Paying points can pay off if you keep the loan long enough to recoup the cost, which often takes several years.
How to Compare Mortgage Offers
Getting multiple quotes is the single most reliable way to save. Lenders price risk differently, so offers on the same loan can vary meaningfully.
- Get at least three quotes within a short window — ideally 14 to 45 days — so credit inquiries are treated as a single shopping event for scoring purposes.
- Ask for a Loan Estimate. This standardized three-page form from the Consumer Financial Protection Bureau lists the rate, monthly payment, closing costs, and APR, making side-by-side comparison straightforward.
- Compare total cost, not just rate. A lower rate with high fees may cost more than a slightly higher rate with low fees.
- Consider a mortgage broker or credit union. Brokers can shop multiple lenders; credit unions and community banks sometimes offer competitive pricing to members.
- Ask about rate locks. A lock protects your rate for a set period, typically 30 to 90 days. Ask what happens if closing is delayed.
When Refinancing Makes Sense
Refinancing replaces your existing loan with a new one, ideally at a lower rate or with better terms. A common rule of thumb is to refinance when you can lower your rate by at least 0.75 to 1 percentage point and plan to stay in the home long enough to recover closing costs — often two to three years. Refinancing to shorten your term, drop PMI, or switch from an ARM to a fixed rate can also be worthwhile even when the rate savings are modest.
What to Remember About Mortgage Rates
Mortgage rates reflect both the broader economy and your own financial picture. The 10-year Treasury yield and Federal Reserve policy set the backdrop, while your credit score, down payment, loan type, and term determine where you land within that range. Fixed-rate loans offer stability; ARMs offer a lower starting rate with future uncertainty. Always compare the interest rate and the APR, request Loan Estimates from multiple lenders, and factor in how long you plan to keep the loan. Small differences in rate and fees compound over decades, so shopping carefully is one of the most effective financial moves a homebuyer can make.
