• Homeowners shouldn't expect much of a difference in mortgage rates after the Federal Reserve's first interest rate cut in years.
• That's because "a lot of these rate cuts are already priced in," Chen Zhao, the economic research lead at Redfin, an online real estate brokerage firm, recently told CNBC. 
• Here's how to know it when it's time to refinance your mortgage, according to experts.

The Federal Reserve cut interest rates by a half percentage point, or 50 basis points, on Wednesday, its first interest rate cut since March 2020. But homeowners shouldn't bet on the move as an opportunity to immediately refinance their mortgage.

That's because "a lot of these rate cuts are already priced in," Chen Zhao, the economic research lead at Redfin, an online real estate brokerage firm, recently told CNBC. 

While mortgage rates are partly influenced by the Fed's policy, they are also tied to Treasury yields and the economy. Home loan rates have already started to come down in recent weeks, slightly induced in part by favorable economic data and indications the Fed could cut rates.

As of Thursday, the average 30-year fixed rate mortgage in the U.S. was 6.20%, according to Freddie Mac data via the Fed. That's down from this year's peak of 7.22% on May 2.

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It can be very difficult to perfectly time a mortgage refinance by looking at mortgage rate activity alone, said Jeff Ostrowski, a housing expert at Bankrate.com.

"It's almost impossible to figure out what mortgage rates are going to do from week to week or month to month," Ostrowski said.

Yet there are ways homeowners can determine when a refinance makes the most sense to them, experts say, especially if more rate cuts are slated before the end of the year.

Here's how to know when it's time to refinance your mortgage, according to experts.

'This is going to be a much smaller wave'

Refinance activity increased to 46.7% of total applications during the week ending Sept. 6, up from 46.4% the week before, according to the Mortgage Bankers Association.

While there has been an increase in refinances as mortgage rates come down, "compared to the massive refinance boom" in 2020 and 2021, "this is going to be a much smaller wave of refinances," said Ostrowski.

Most homeowners have a mortgage rate below 5%, said Jacob Channel, senior economic analyst at LendingTree.

A refinance will mostly benefit a "small number of people" who bought homes "when rates were at 8%," said Ostrowski.

Whether it's smart for homeowners to refinance their mortgage will depend on factors such as their existing borrowing and repayment timeline, experts say.

How to know when it's time to refinance

If you are thinking about refinancing, look carefully at what's going on with rates in the market, reach out to lenders and see if doing so now or in the near future makes the most sense for you, Channel said.

"The only person who can decide whether or not refinancing is going to be worth it is you, based on what's going on in your life," he said.

Here are three criteria that can help you determine if a refinance makes the most sense to you:

1. You can cut your rate by 50 basis points or more

To know when it makes sense to refinance, homeowners need to see a notable drop in mortgage rates in order to benefit, experts say. The prevailing rate should be at least 50 basis points below your current rate, Zhao said.

But that's not a "hard and fast rule," Channel said.

Some experts set a higher bar: It "makes sense" to consider a refinance if rates have fallen one to two points since you took out the mortgage, Ostrowski said.

Even if your existing mortgage has a high rate, you might want to consider waiting until the central bank is further along in its cuts. The expectation is that rates are to steadily decline throughout the rest of 2024 and into 2025, according to Zhao.

2. You can afford refinance costs

There are two ways to pay for a refinance: with cash up front, or by rolling the expense into your new loan, boosting your monthly mortgage payment.

There's no such thing as a free lunch when it comes to refinancing a loan, Melissa Cohn, regional vice president of William Raveis Mortgage in New York, told CNBC in August.

Generally, a refinance is going to cost between 2% and 6% of the loan amount that you are refinancing, said Channel.

For example: If your current loan amount is $250,000 and you're refinancing the total amount, expect to pay anywhere between 2% and 6% of $250,000, or roughly $5,000 to $15,000.

If you plan to refinance, make sure you can afford the associated costs, such as closing costs, an appraisal and title insurance. The total cost will depend on your area.

3. Your savings will outweigh the costs

You can also look into your "break-even point," or the moment your savings eclipse the cost of the refinance, said Channel.

Here's an example on doing that math: If you decide to refinance your mortgage and it costs $6,000 and you're saving $200 a month, divide $6,000 by $200. The result is the number of months that you have before your refinance has "paid for itself."