Mortgage Interest Rates Explained: What Determines Your Rate?

If you're shopping for a home, you've probably noticed that mortgage interest rates are one of the first numbers people talk about.

You may see a rate advertised online, hear a different rate from a lender, or receive multiple offers with slightly different rates. So, how does your mortgage interest rate actually get determined?

The answer depends on a combination of market conditions, your financial profile, the type of mortgage you're getting, and the specific terms of the loan.

Understanding these factors can help you compare mortgage offers more effectively and understand why the rate you're offered may be different from the rate you saw advertised.

What Is a Mortgage Interest Rate?

A mortgage interest rate is the cost of borrowing money to purchase a home, expressed as a percentage.

For example, if you borrow $300,000 at a 6% interest rate, the interest rate determines how much interest is charged on the outstanding loan balance over time.

Your mortgage payment typically includes both:

• Principal: the amount you borrowed that you're paying back

• Interest: the cost of borrowing the money

Your total monthly housing payment may also include property taxes, homeowners insurance, mortgage insurance, and HOA fees, depending on your loan and property.

The interest rate itself does not include all of the other costs associated with getting a mortgage. That's where APR becomes important.

Mortgage Interest Rate vs. APR: What's the Difference?

These two numbers are often confused, but they are not the same.

Interest Rate

Your mortgage interest rate is the percentage used to calculate the interest charged on your loan.

It does not include other loan costs or fees.

APR

Annual Percentage Rate (APR) is a broader measure of the cost of borrowing.

It incorporates the interest rate plus certain additional costs associated with the loan, such as points, mortgage broker fees, and other charges. Because of this, the APR is generally higher than the stated interest rate.

You can find the interest rate on page 1 of your Loan Estimate under Loan Terms, while the APR appears on page 3 under Comparisons.

Why Does the Difference Matter?

Imagine two mortgage offers:

Loan A

• Interest rate: 6.50%

• APR: 6.70%

Loan B

• Interest rate: 6.50%

• APR: 6.85%

The interest rate is the same, but the APR is different because the overall loan costs are different.

That's why you shouldn't compare mortgage offers based solely on the advertised interest rate.

What Determines Your Mortgage Interest Rate?

Mortgage rates are influenced by both market conditions and borrower-specific factors.

Let's look at some of the biggest factors.

1. Market Conditions

Mortgage rates don't exist in a vacuum.

Economic conditions and financial markets influence the rates lenders offer to borrowers.

Inflation, economic growth, monetary policy, and conditions in the bond market can all affect mortgage rates.

This is one reason mortgage rates can change from one week—or even one day—to another.

Freddie Mac notes that mortgage rates are determined by a combination of factors, including economic conditions, lender considerations, and borrower characteristics.

This also means that a mortgage rate you see today may not be the same rate available when you're ready to lock your loan.

2. Your Credit Profile

Your credit history and credit score can influence the mortgage rate you are offered.

Generally, a stronger credit profile can help a borrower qualify for more favorable pricing, although the exact impact depends on the loan program and other factors.

This is one reason it's useful to review your credit before applying for a mortgage.

Your credit score isn't the only factor that matters, but it can be an important part of the lender's assessment of risk.

3. Your Down Payment

Your down payment can also affect mortgage pricing.

A larger down payment generally means you're borrowing a smaller percentage of the home's value.

Your loan-to-value ratio (LTV) is one of the factors lenders may consider when determining loan terms and pricing.

However, putting more money down isn't automatically the best choice for every borrower.

You also need to consider how much cash you want to keep available for closing costs, emergency savings, moving expenses, and other financial goals.

4. Your Loan Type

The type of mortgage you choose can affect the rate you're offered.

For example, rates can differ depending on whether you're considering:

• Conventional loans

• FHA loans

• VA loans

• USDA loans

• Fixed-rate mortgages

• Adjustable-rate mortgages (ARMs)

These loans have different eligibility requirements, structures, and risk characteristics.

That's why comparing a rate from one loan type directly with a rate from another may not give you a complete picture.

5. Your Loan Term

The length of your mortgage can also affect your interest rate.

A 30-year fixed-rate mortgage and a 15-year fixed-rate mortgage, for example, generally have different rates and monthly payments.

A shorter loan term may come with a different interest rate, but the monthly payment is typically higher because you're paying the loan back over a shorter period.

When comparing terms, look at both the monthly payment and the total cost over time.

6. The Property You're Buying

The property itself can be part of the mortgage pricing equation.

Factors such as property type, occupancy, loan amount, and other characteristics can affect eligibility and pricing depending on the loan program.

For example, financing a primary residence may be treated differently from financing an investment property.

Your mortgage professional can explain which property-specific factors apply to your loan scenario.

Why Does a Small Rate Difference Matter?

Even a relatively small difference in interest rate can affect your monthly payment and the total amount of interest you pay over the life of a mortgage.

For example, Freddie Mac illustrates how changes in mortgage rates can change the monthly principal-and-interest payment on the same loan amount.

Consider a hypothetical $300,000 30-year fixed-rate mortgage:

Interest Rate	Approx. Principal & Interest Payment
6.00%	$1,799
6.50%	$1,896
7.00%	$1,996
7.50%	$2,098

These are simplified examples of principal-and-interest payments only. They do not include property taxes, homeowners insurance, mortgage insurance, HOA fees, or other costs.

The point is that a small change in the interest rate can have a meaningful effect on your monthly payment.

What Are Discount Points?

You may hear a lender mention discount points when discussing your mortgage rate.

A discount point is an upfront fee paid to the lender in exchange for a lower interest rate.

Generally, one point equals 1% of the loan amount.

For example, one point on a $300,000 mortgage would be $3,000.

Paying points means paying more upfront in exchange for a lower rate. Whether that makes financial sense depends on factors such as how long you expect to keep the mortgage, how much cash you have available at closing, and the specific rate reduction being offered.

Points vs. No Points

Imagine you're comparing:

Option A

• Higher interest rate

• No discount points

• Lower upfront cost

Option B

• Lower interest rate

• Discount points paid at closing

• Higher upfront cost

The lower rate isn't automatically the better choice.

You need to consider how much the points cost and how long it could take for the monthly savings to make up for that upfront expense.

What Are Lender Credits?

Lender credits work in the opposite direction.

Instead of paying more upfront to receive a lower rate, you may accept a higher interest rate in exchange for a credit toward certain closing costs.

In other words:

Pay more upfront → potentially lower rate

Pay less upfront → potentially higher rate

The right structure depends on your financial situation, how long you expect to keep the mortgage, and the specific loan offers available to you.

What Is a Mortgage Rate Lock?

Mortgage rates can change frequently.

A rate lock is an agreement that keeps your interest rate from changing between the time you lock it and closing, as long as you close within the specified period and your application doesn't undergo changes that affect the terms.

Rate locks are commonly available for periods such as 30, 45, or 60 days, although options vary by lender.

For example, if you lock your rate at 6.50%, that rate generally won't change before closing as long as you meet the conditions of the lock.

What Happens If Rates Go Down?

A rate lock can provide protection if rates increase, but it can also mean you don't automatically benefit if rates decrease.

Some lenders offer options such as a float-down, but availability and terms vary.

Always ask your lender what happens if market rates change after your rate is locked.

Can Your Rate Change After You Lock It?

A rate lock doesn't necessarily mean that nothing about your loan can ever change.

According to the CFPB, a locked rate can still change in certain circumstances, including changes to your loan amount, credit score, down payment, or documented income. Changes to the loan type or other application details can also affect the rate.

That's why it's important to maintain your financial situation and communicate with your lender throughout the closing process.

Why Is the Rate Online Different From the Rate I Was Offered?

This is a common question.

An advertised mortgage rate may be based on a specific set of assumptions, such as:

• Particular credit score

• Specific down payment

• Certain loan type

• Owner-occupied property

• Specific loan amount

• Discount points

• Rate-lock period

• Other borrower or property characteristics

If your situation differs from those assumptions, your rate may also be different.

Freddie Mac notes that lenders determine rates for individual borrowers based on factors including credit and prevailing market conditions.

An advertised rate is therefore best viewed as a starting point for comparison—not a guarantee of the rate you'll receive.

How to Compare Mortgage Rates

When comparing mortgage offers, don't look at the interest rate alone.

Consider:

Interest Rate

What rate are you actually being offered?

APR

What does the APR indicate about the broader cost of the loan?

Points

Are you paying upfront points to receive the advertised rate?

Lender Credits

Are you receiving credits in exchange for accepting a higher rate?

Closing Costs

How much will you need to pay upfront?

Monthly Payment

What will your estimated total monthly housing payment be?

Loan Term

How long will you have the mortgage?

Rate Lock

Is your rate locked? If so, for how long and under what conditions?

The CFPB recommends requesting and comparing Loan Estimates and making sure you're comparing the same type of loan and similar terms.

Should You Wait for Mortgage Rates to Go Down?

It's tempting to try to predict where mortgage rates are headed.

But no one can know exactly what rates will be available in the future.

Instead of basing a home purchase entirely on the hope that rates will fall, consider whether the home and mortgage are affordable based on your current financial situation.

If rates change in the future, homeowners may have refinancing options depending on market conditions, their loan, home value, and financial circumstances.

The most important thing is to choose a mortgage that fits your financial situation rather than trying to perfectly time the market.

Questions to Ask Your Mortgage Professional

Before choosing a mortgage, consider asking:

• Is this interest rate fixed or adjustable?

• Is the rate currently locked?

• How long does the rate lock last?

• Are there points included in this rate?

• What is the APR?

• What are my estimated closing costs?

• Are lender credits available?

• How much will my estimated monthly payment be?

• What factors could cause my rate to change?

• Am I comparing the same loan type and terms as another lender's offer?

Getting answers to these questions can make it easier to compare your options beyond the headline rate.

The Bottom Line

Your mortgage interest rate is important, but it's only one part of the cost of a mortgage.

The rate you receive can be influenced by market conditions, your credit profile, down payment, loan type, loan term, property characteristics, and other factors.

When comparing mortgage options, look at the complete picture—including the interest rate, APR, points, lender credits, closing costs, monthly payment, and rate-lock terms.

At Fair Mortgage Lending, our mortgage professionals can help you understand how these factors apply to your specific situation and compare available loan options.

Ready to explore your mortgage options? Contact Fair Mortgage Lending to get started.