The old rule of thumb says to refinance when mortgage rates drop by 1%. That is too simplistic. A 0.50% rate drop can be worth refinancing on a large loan with low closing costs and a long expected holding period. It can be a bad deal on a smaller loan, expensive refinance, or home you may sell soon.
The right question is not “How much did the rate drop?” It is “How long until the savings exceed the cost?”
If you are comparing points, read Mortgage Points Calculator 2026. If you want cash from home equity, see HELOC vs Cash-Out Refinance in 2026.
The Break-Even Formula
Use:
break-even months = refinance closing costs / monthly payment savings
Example:
- Refinance cost: $5,000
- Monthly savings: $150
- Break-even: 33.3 months
If you keep the loan longer than about 34 months, the refinance may save money. If you sell or refinance again before then, it may not.
A Half-Percent Drop Can Matter More on Large Loans
The bigger the loan, the more valuable a rate drop becomes.
| Loan balance | Rate drop | Approximate impact |
|---|---|---|
| $150,000 | 0.50% | Smaller monthly savings |
| $400,000 | 0.50% | Meaningful monthly savings |
| $800,000 | 0.50% | Large monthly savings |
Closing costs also matter. A no-point, low-cost refinance can make a smaller rate drop work. A refinance with high points and fees may require a much larger rate drop.
Watch the Loan Term Reset
Refinancing into a new 30-year loan can lower the monthly payment while increasing the total time in debt. That is not always bad, but it should be intentional.
Compare:
- new 30-year payment
- new 20-year payment
- new 15-year payment
- payment needed to keep your original payoff date
If you refinance mainly for a lower rate, consider paying enough extra principal to stay on the original schedule.
Points Can Distort the Quote
Some refinance offers advertise a low rate because they include discount points. Points are upfront fees. A lower rate with high points may not beat a slightly higher no-point rate if you refinance again soon.
Compare Loan Estimates side by side:
- interest rate
- APR
- points
- lender fees
- third-party fees
- lender credits
- cash to close
- escrow changes
For details, see Mortgage Points Calculator 2026.
Cash-Out Refinancing Is a Different Decision
A rate-and-term refinance replaces your mortgage mainly to change rate, term, or payment. A cash-out refinance increases the loan balance so you receive cash.
Do not judge a cash-out refinance only by the mortgage rate. You are also borrowing more against the home, increasing risk, and potentially changing tax treatment.
When a 0.50% Drop May Be Worth It
A half-percent rate drop may be worth refinancing when:
- closing costs are low
- you will keep the loan beyond break-even
- the loan balance is large
- you are not paying large points
- the new term fits your payoff plan
- the refinance improves monthly cash flow without increasing long-term cost too much
When to Skip It
Skip or wait when:
- you may move soon
- closing costs are high
- points create a long break-even
- your credit score may improve soon
- your current loan has special benefits
- the refinance restarts a 30-year term you do not need
Bottom Line
A 0.50% mortgage rate drop can be enough to refinance, but only if the break-even math works. Compare total costs, not just rate. The best refinance is the one that improves your plan over the time you actually expect to keep the loan.
Related Reading
- Mortgage Points Calculator 2026
- HELOC vs Cash-Out Refinance in 2026
- Standard Deduction vs Itemizing 2026
- Treasury Bills vs CDs vs High-Yield Savings in 2026
Sources
- CFPB, choosing and comparing mortgage loan offers: https://www.consumerfinance.gov/owning-a-home/compare/
- CFPB, points and lender credits: https://www.consumerfinance.gov/ask-cfpb/how-should-i-use-lender-credits-and-points-also-called-discount-points-en-136/
- IRS Publication 936, refinance and mortgage interest rules: https://www.irs.gov/publications/p936