RATE ENVIRONMENT MATH · RATES CHECKED 30 SEPTEMBER 2026
When a Variable HELOC Beats a Fixed Home Equity Loan (And When It Does Not)
Variable wins if rates drop enough, long enough. Otherwise lock. This page defines “enough” quantitatively and gives you an interactive model to run your own numbers against the September 2026 rate environment.
September 2026 Rate Context
Fed funds: 3.75-4.00% | Prime: 7.00% | Typical HELOC APR: 9.50-10.50%
Prime Rate History 2020-2026
Anyone who held a HELOC from 2020 through 2023 watched their rate move 525 basis points in 16 months. The variable-rate advantage of 2020-2021 evaporated by mid-2022 and turned negative through 2023. This is the volatility argument in concrete terms.
| Period | WSJ Prime | Typical HELOC APR | Context |
|---|---|---|---|
| Jan 2020 | 4.75% | 7.25-8.25% | Pre-pandemic |
| Mar 2020 | 3.25% | 5.75-6.75% | Emergency Fed cut (COVID) |
| Dec 2020 | 3.25% | 5.75-6.75% | Floor maintained |
| Dec 2021 | 3.25% | 5.75-6.75% | Rates still at floor |
| Jun 2022 | 4.75% | 7.25-8.25% | First hikes begin |
| Dec 2022 | 7.50% | 10.00-11.00% | +425bp in 9 months |
| Jun 2023 | 8.25% | 10.75-11.75% | Near peak |
| Sep 2023 | 8.50% | 11.00-12.00% | Cycle peak |
| Jan 2024 | 8.50% | 11.00-12.00% | Held at peak |
| Sep 2024 | 8.00% | 10.50-11.50% | First cut (50bp) |
| Dec 2024 | 7.50% | 10.00-11.00% | Additional cuts |
| Dec 2025 | 6.75% | 9.25-10.25% | Cut to 6.75% (Dec 10) |
| Jun 2026 | 6.75% | 9.25-10.25% | Held through the first half of 2026 |
| Sep 2026 | 7.00% | 9.50-10.50% | Current. Hike to 7.00% effective Sep 17, first since 2023 |
Typical HELOC APR is prime plus a 2.50 to 3.50 percent margin, not a surveyed rate. Prime from the Federal Reserve H.15 release of 29 September 2026. Checked 30 September 2026.
Break-Even Calculator
Enter your loan parameters. The calculator shows total interest under each scenario, the break-even prime level, and a sensitivity table.
Expected-Value Framework
Walk through a worked example. Suppose a borrower has a $60,000 balance. The HELOC margin is 2.75%, so current APR is prime 7.00% + 2.75% = 9.75%. A comparable HEL is offered at 8.75% fixed for 10 years, with $1,200 in closing costs.
At current rates, the HELOC costs more than the HEL. For the HELOC to win over 5 years, prime must average below 5.50% (meaning the HELOC APR averages below 8.25%, enough to offset the HEL's lower fixed rate and closing-cost disadvantage). That requires the Fed to cut rates by roughly 150bp from current levels and sustain them there, and the Fed has just moved 25bp in the other direction.
This is an honest calculation. The spread is not zero, but the required rate path is specific. Most people do not have conviction on a 125bp cut path. Without conviction, locking the HEL is the more defensible choice.
Honest caveat
This framework assumes you have a view on rates. Most people do not. Rate forecasters are consistently wrong beyond 12 months. If you do not have strong conviction on the rate path, the risk-adjusted choice is usually the fixed-rate HEL, because you are not paying to hold a rate view you do not actually have.
Payment-Shock Scenarios at Draw-Period End
The draw-to-repayment transition is a separate risk from rate environment. Even if rates stay flat, the payment increase at month 121 is structural. Here are three scenarios on a $75,000 balance with 2.75% margin and 20-year repayment.
| Scenario | Prime | APR | Interest-only | P+I payment | Shock |
|---|---|---|---|---|---|
| Rates unchanged | 7.00% | 9.75% | $609 | $711 | +$102 (+17%) |
| Rates +100bp | 8.00% | 10.75% | $672 | $761 | +$90 (+13%) |
| Rates -100bp | 6.00% | 8.75% | $547 | $663 | +$116 (+21%) |
Balance $75,000, margin 2.75%, 20-year repayment period.
Six Real-World Decision Triggers
Job stability is high, income predictable
Lean HEL: remove rate uncertainty when you have capacity to absorb rate risk through income but prefer not to.
Project timeline is under 24 months
Lean HELOC: short enough that rate volatility has less compounding time. Especially true if rates are trending flat-to-down.
You have a strong rate view (below 5.50% avg prime)
Lean HELOC: but be honest about your conviction. Macro forecasting is hard. Most people overestimate their rate view quality.
You are 8+ years into a HELOC draw period
Convert or refinance now. Payment shock is 2+ years away. Your options are better now than at the transition.
You hold alternative investments with known return >10%
HELOC keeps lower cost of capital. But post-TCJA, HELOC interest used for investing is not deductible. Run the after-tax math.
You plan to sell the property within 3 years
HELOC: lower or zero closing costs makes short-horizon borrowing far cheaper, assuming rates do not spike.
FAQ
Related: Reset Mechanics · Convert to Fixed · Lender Shootout · Standby Liquidity · Home