Every refinance decision comes down to one calculation: break-even months, compared to your expected time in the home. But the surrounding context — your current rate, loan type, equity position, and financial goals — determines whether that calculation even needs to be run. Here's how to tell when it's time to sit down with a lender versus when to stay put.
The One Rule That Actually Matters
Refinance when your break-even period is shorter than the time you plan to keep the loan. Everything else is noise.
Break-even period = Total closing costs ÷ Monthly payment reduction. If break-even is 28 months and you'll keep the home 10 more years, refinancing saves money. If break-even is 42 months and you'll sell in 3 years, it doesn't.
Rules of Thumb That Don't Work
The mortgage industry loves simple thresholds. Most of them are wrong:
"Refinance when rates drop 1%"
Too crude. A 0.5% drop is easily worth it on a large loan with low closing costs. A 1% drop might not be worth it on a small loan with a 2-year expected hold.
"Refinance to save $100/month"
Ignores closing costs. $100/month savings at $15K in costs has a 150-month break-even — you'll move long before then.
"Refinance every 5 years"
Based on nothing. Refinancing without a rate benefit just resets amortization and adds closing costs.
"If rates drop, always refinance"
Ignores your existing rate, hold period, and closing costs. The refi economics depend on all three.
The Signals That Do Matter
Signal 1: Your Rate is Above Market by 0.5%+
If you borrowed in 2022-2023 at 7%+ and current rates are 6.25-6.50%, the 0.50%+ gap likely produces a break-even inside 36 months on a typical San Diego loan. Worth running the numbers.
Signal 2: You Have an FHA or VA Loan and Rates Dropped
Streamline refinances (VA IRRRL, FHA Streamline) have such low closing costs that even 0.25-0.50% rate drops can hit break-even in under 2 years. If you qualify for a streamline, the threshold for refinancing is lower than conventional borrowers face.
Signal 3: You Can Drop Mortgage Insurance
Two versions of this:
- Conventional PMI — If you've crossed 80% LTV through principal paydown or appreciation, ask your current lender to cancel PMI. If they refuse, a refinance may be justified even without a rate drop. In many cases PMI removal alone saves $150-$500/month.
- FHA MIP — FHA MIP stays for the life of the loan on new FHA originations. If you have 20%+ equity, refinancing to a conventional loan drops MIP permanently. Over 20+ years of loan life, this typically beats the closing costs significantly.
Signal 4: You're Getting Out of an ARM
If your 5/1 or 7/1 ARM is approaching its initial fixed period's end, rate adjustments are imminent. Refinancing to a fixed-rate eliminates that uncertainty. This can be worth doing even if your fixed-rate refinance is slightly higher than your current ARM rate — you're buying stability, not just a lower number.
Signal 5: You Need the Cash and Your Current Rate is at or Above Market
If you need to access equity for a legitimate purpose and your current rate isn't below today's market, a cash-out refinance can make sense. If your rate is well below market, a HELOC or home equity loan usually wins instead.
Signal 6: You Want to Change Loan Term
Moving from 30-year to 15-year (or 20-year) shortens the term and saves substantial lifetime interest. This can be worth doing even at a slightly higher total monthly payment, because most of that payment is going to principal rather than interest. The right move for borrowers with strong cash flow and long intended tenure.
The Signals That Should Stop You
- You'll move within 2 years. Break-even rarely works on short timelines.
- Your current rate is below market. Almost every 2020-2021 borrower is here. Unless you have another reason (cash-out with clear purpose, PMI elimination), stay put.
- Your credit score has dropped significantly. The quote you'll get may not be the quote you're imagining.
- You're restarting amortization on a nearly-paid-off loan. Going from 10 years remaining to a fresh 30-year mortgage can cost more in total interest even at a much lower rate.
- You're being pitched by an aggressive mailer. The best refinance opportunity is rarely the one that shows up uninvited.
The Break-Even Worksheet
Before talking to a lender, do this math yourself:
- Get your current payment. Principal + interest only (not taxes/insurance).
- Get your current balance and rate. From your most recent statement.
- Estimate a new rate. Pull current rates from 2-3 lender websites; use the conservative number.
- Estimate the new payment. Use the refinance calculator.
- Estimate closing costs. 2-3% of new loan amount for conventional, 0.75-1.75% for VA IRRRL, 1-2.5% for FHA Streamline.
- Divide costs by monthly savings. That's your break-even in months.
- Compare to your expected hold period. If break-even < 60% of expected hold, refinance almost certainly makes sense. If > 90%, almost certainly not.
Scenarios We See Often
Scenario 1: Bought 2023-2024 at Elevated Rates
If you bought in 2023 at 7.125% and rates today are 6.25%, your savings on a $700K San Diego loan are roughly $420/month. Closing costs of ~$18K give you a break-even of 43 months. If you plan to keep the home 7+ years, refinance makes sense.
Scenario 2: Bought 2020-2021 at Ultra-Low Rates
If you have a 3.25% rate, no rate-and-term refinance today makes sense. Period. If you need cash, use a HELOC or home equity loan — your primary mortgage should stay exactly where it is.
Scenario 3: FHA Borrower from 2022
If rates have dropped 0.50%+ since your FHA closing, an FHA Streamline is likely worth running. If you have 20%+ equity now (common in appreciating SD markets), a conventional refinance to drop MIP permanently may beat the Streamline long-term.
Scenario 4: VA Borrower from 2023-2024
Even modest rate drops justify an IRRRL. If you're exempt from the funding fee (disability compensation), break-even often hits inside 12-18 months.
Scenario 5: 5/1 ARM Expiring in 12-18 Months
Regardless of current rates, this is worth evaluating now. Rate adjustments on ARMs can add 1-2% to your payment overnight, and planning ahead is easier than reacting.
How Often Can You Refinance?
No legal limit on how many times you can refinance, but lenders impose "seasoning" requirements:
- Conventional rate-and-term: Typically no seasoning
- Conventional cash-out: Usually 6 months of payments
- FHA Streamline: 210 days + 6 payments on current loan
- FHA cash-out: 12 months of on-time payments
- VA IRRRL: 210 days + 6 payments on current VA loan
The Bottom Line
The best time to refinance is when your break-even math is shorter than your expected hold period, and you have a specific reason — lower rate, dropped mortgage insurance, escape from an ARM, or legitimate cash-out need. Calendar time and industry rules of thumb are poor substitutes for real numbers.
Use the refinance calculator to run your specific scenario before talking to any lender. A 15-minute exercise at the kitchen table will tell you more than a dozen sales calls.