Fixed rate and variable rate mortgages are both used to finance a home, but they manage risk in two completely different ways.
A fixed rate stays the same for the life of the loan. A variable, or adjustable, rate starts at a lower rate and then changes with the market. If you’re looking for certainty in your payment amount, choose a fixed rate.
Fixed Rate Mortgages vs. Variable Rate Mortgages
A fixed rate mortgage keeps the interest rate and principal and interest payment amount unchanged for the entire term of the loan, whether it’s 15 years, 20 years, or 30 years. A variable-rate mortgage, commonly called an adjustable-rate mortgage (ARM), has a lower rate for an initial period, usually 5, 7, or 10 years, and then increases or decreases based on a market index.
Currently, the Freddie Mac Weekly Rate Survey has the average 30-year fixed-rate mortgage rate at 6.43%, down from the previous week (6.49%) and the year before (6.67%). This rate is the primary benchmark for comparing most fixed-rate mortgage offers. ARM initial rates are typically lower than this benchmark rate, although the exact difference depends on the lender, the index used, and your credit score.
What is a variable-rate mortgage?
A variable-rate mortgage, also known as an adjustable-rate mortgage (ARM), is a type of home purchase loan in which the interest rate is fixed for an initial period and then periodically resets over the life of the loan. One of the most common structures is a 5/1 ARM, which means the interest rate stays the same for five years and then adjusts annually.
So is your mortgage fixed or variable? The answer depends entirely on the type of agreement you sign. Most buyers still choose fixed-rate loans, but as fixed rates rise above 6%, ARMs have become more popular as a way to reduce your down payment. The loan type and rate adjustment schedule will always be clearly stated in your Loan Estimate and Closing Disclosure.
How are variable mortgage rates determined?
After the initial period ends, your new rate is calculated using the formula Index + Margin. The Index is a market rate that changes independently, while the Margin is a fixed number that the lender sets at the time of signing the agreement and does not change for the life of the loan.
Most ARMs issued today are tied to the Secured Overnight Funding Rate (SOFR). Data from the Federal Reserve Bank of New York shows that the SOFR was 3.66% on July 1, 2026. If you add the margin set by the lender, which is usually between 2 and 3 percentage points, to that, the result (after rounding up according to the terms of the loan agreement) will be your final rate at each adjustment, subject to the rate increase caps explained below.
Index: SOFR (the most common index today), a rate based on Treasury bills, or one of the older indexes that replaced LIBOR in older loans.
Margin: The fixed rate difference that the lender sets when the loan is made and is included in the final loan documents.
Adjustment frequency: After the initial fixed period ends, it usually happens once a year, although some ARMs adjust every six months.
What is a fixed-rate mortgage?
A fixed-rate mortgage maintains a single interest rate for the entire term of the loan. Your principal and interest payments in the first year are exactly the same as you will pay in the 30th year. Lenders offer a variety of repayment terms, from short-term options to 30 years, and a professional mortgage broker can help you choose the best option between a shorter term and a lower monthly payment.
Because the interest rate never changes, the initial rate on these loans is usually slightly higher than the initial rate on an ARM. People who value budget stability or plan to stay in their home for a long time often prefer this option. If you want to compare fixed loan pricing on standard loans and jumbo loans, consult with an expert on conventional loans.
Real Numbers: Comparing Fixed-Rate and Variable-Rate Mortgage Payments
Maria, an emergency room nurse, wants to buy a $420,000 home and is putting down 10%, so her loan amount will be $378,000. She receives two offers: a 30-year fixed loan at 6.43% and a 5/1 ARM with an initial rate of 5.75%.
30-year fixed loan at 6.43%: About $2,371 per month in principal and interest.
5/1 ARM at 5.75%: About $2,205 per month over the first five years; that’s about $166 per month in savings, or about $9,960 over five years.
If Maria sells the home or refinances her mortgage within five years, the ARM will save her real money. But if he stays in the house and the interest rate increases by the current 2 percentage point cap, his rate could jump to 7.75%, and his monthly payment could increase to about $2,706—about $335 more than he would have paid if he had taken out a fixed-rate loan from the start. That’s the trade-off every variable-rate borrower makes.
A tip from industry insiders: Before comparing loan offers, ask your loan officer to calculate the worst-case payment amount after the rate adjustment, not just the attractive initial rate. Your decision should be based on that worst-case scenario, not the number on the rate slip.
How do ARM rate caps protect your payment?
Adjustable-rate mortgages have caps that limit how much your interest rate can increase. The CFPB’s guidance breaks these caps down into three categories.
Initial Adjustment Cap: Limits the amount of rate change in the first adjustment; usually between 2 and 5 percentage points.
Periodic or Subsequent Cap: Limits the amount of increase in each subsequent adjustment; usually between 1 and 2 percentage points.
Lifetime Cap: Limits the maximum rate increase over the life of the loan; usually 5 to 6 percentage points above the initial rate.
These caps don’t guarantee that your payments will always remain affordable, but they do prevent a bad market period from doubling your payment overnight. Always ask your lender for the exact cap structure, usually written as numbers like 2/2/5, before you sign the contract.
Choosing between a fixed rate and a variable rate based on your circumstances
The length of time you plan to own your home is the most important factor. If you sell your home or refinance your loan before the fixed term of an ARM ends, you probably won’t ever see a rate increase. But if you plan to stay in your home for the long term, a fixed-rate loan is more likely to be the right choice.
After that, it’s up to your risk tolerance and budget. People who need a steady, predictable amount of money for their financial planning will usually benefit more from a fixed-rate loan, even with a slightly higher upfront cost. If your income fluctuates, such as from renting out your property, using a Bank Statement loan with a fixed rate can simplify your monthly financial calculations.
Investors who base their decision on rental income should also consider the reliability of their tenants. If you’re using an Investor Cash Flow Loan, the long-term stability of your rental income should play a role in your decision to choose a fixed or variable rate. Many investors who use an investment property loan or a second home loan for recreational rentals choose a fixed rate to keep their payments predictable despite seasonal fluctuations in rental income.
If you qualify based on the property’s cash flow, not your personal income, ask about a Debt Service Coverage Ratio (DSCR) loan. In a DSCR loan program, the property’s rental income is compared to the proposed loan payment, and this type of loan is offered in both fixed and adjustable rates; so even if you don’t qualify for a loan based on your personal income, you still need to decide between a fixed and variable rate.
Finally, keep an eye on market trends. Locking in a fixed rate protects you from future increases, but if rates go down, you’ll only be able to benefit from it through a refinance. In contrast, an ARM allows you to take advantage of falling rates without having to refinance, but you are equally exposed to risk if rates rise.
