If you bought or refinanced a home between roughly 2020 and 2022, there’s a decent chance you’re sitting on a mortgage rate that will never come back: something with a 2 or a 3 in front of it. And if you’re now looking at a kitchen that needs redoing, a pile of higher-rate debt, or a tuition bill, you’ve probably run into the same uncomfortable question I keep getting asked: how do I get at my home’s equity without giving up that rate?
Because that’s the trap. The two obvious ways to tap equity — a cash-out refinance and a HELOC — are not just two flavors of the same thing. One of them quietly re-prices your entire mortgage at today’s rate. The other doesn’t. Getting that distinction wrong is one of the more expensive mistakes I see people talk themselves into, precisely because a cash-out refi sounds like the simpler, more grown-up option.
One thing up front: I’m a retired chartered accountant, not your accountant, and this is general information, not personalized financial or tax advice. Every rate and rule below is sourced, and I’ve noted the date I checked each one. Your actual numbers depend on your lender, your credit, and your situation — so treat the worked example as a way to see the mechanics, not as a quote.
What’s the real difference between a HELOC and a cash-out refinance?
A cash-out refinance replaces your existing mortgage with one new, larger loan and hands you the difference in cash. A HELOC leaves your existing mortgage completely alone and adds a separate, revolving line of credit secured by your home.
That single structural difference is the whole ballgame when you have a low first-mortgage rate. With a cash-out refinance, your old loan is paid off and gone — including its rate. With a HELOC, your old loan keeps running exactly as it was, at the rate you locked in, and the new borrowing sits alongside it.
Here’s the quick version before we put numbers on it:
| Cash-out refinance | HELOC | |
|---|---|---|
| What happens to your current mortgage | Paid off and replaced | Untouched — same rate, same term |
| Rate on your existing balance | Re-priced to today’s rate | Stays at your original rate |
| Rate type | Usually fixed | Usually variable (prime + margin) |
| How you get the money | Lump sum at closing | Draw as needed, like a credit line |
| Best when… | Your current rate is already near today’s | You want to protect a low rate |
Why does a cash-out refinance re-price your whole mortgage?
Because a refinance, by definition, pays off your old loan and writes a brand-new one — and the new one carries today’s rate on the entire balance, not just the cash you pull out. This is the single most important thing to understand, and it’s the part the word “refinance” hides.
Let me make it concrete with a worked example. These are illustrative figures, not a quote, and I’ve assumed fresh 30-year amortization on each option so the comparison is clean.
Say you owe $280,000 at 3.25%, and you need $60,000 for a renovation.
- Cash-out refinance: You take out one new loan for $340,000 (your $280,000 balance plus the $60,000). That whole $340,000 is now priced at today’s rate — roughly 7%. (Freddie Mac’s Primary Mortgage Market Survey put the average 30-year fixed at 7.03% for the week of September 24, 2026; cash-out loans often price a touch higher still.)
- HELOC: Your $280,000 stays at 3.25%, untouched. You open a separate line for the $60,000, priced at the HELOC rate — say prime plus a margin. With prime at 7.00% (effective September 17, 2026) and, for this example, a 1.5-point margin, that’s about 8.5%, and it applies only to the $60,000.
Now watch what happens to the money you already borrowed — the $280,000 that had nothing to do with your renovation:
| Cash-out refinance | HELOC | |
|---|---|---|
| Your original $280,000 | Re-priced to ~7% | Stays at 3.25% |
| First-year interest on that $280,000 | ~$19,600 | ~$9,100 |
| Extra interest just to touch your rate | ~$10,500/yr | $0 |
| The new $60,000 | Folded into the 7% loan | Separate line at ~8.5% |
| Rough monthly payment | ~$2,262 | ~$1,219 + ~$425 interest-only ≈ ~$1,644 |
Look at that “extra interest” line. Before you’ve spent a single dollar on the renovation, the cash-out refinance is costing you roughly $10,500 more per year in interest — purely as a toll for disturbing a rate you already had. The $60,000 you actually wanted costs about the same either way; it’s the $280,000 you weren’t trying to borrow against that gets punished.
That’s the wedge, and it’s why “just refinance and take cash out” is often the wrong instinct in a world where your existing rate is far below the market. You don’t re-price your whole balance to borrow a slice of it.
When does a HELOC actually win?
A HELOC wins when you have a low first-mortgage rate worth protecting and you’re borrowing a modest amount relative to your total balance. In the example above — and in most 2-and-3% mortgage situations — it’s the clear cost winner.
It’s also the better fit when:
- You don’t need all the money at once. A HELOC is revolving. You draw what you need during the draw period and pay interest only on what you’ve actually used — useful for a renovation that pays out in stages, or an emergency buffer you may never fully tap.
- You expect to pay it back relatively quickly. The less time the higher-rate balance is outstanding, the less its rate matters.
- You can handle a variable rate. Most HELOCs move with prime. If prime rises, your payment rises. That’s the main risk to weigh.
The honest catch: because a HELOC is usually variable and prime can climb, a balance you carry for many years carries rate uncertainty a fixed loan doesn’t. If you’ll owe it for a decade, that matters more.
When does a cash-out refinance actually win?
A cash-out refinance wins when there’s no low rate left to protect — that is, when your existing rate is already at or above today’s rates — or when a single, fixed, predictable payment is worth more to you than the interest math.
Specifically, consider a cash-out refi when:
- Your current rate isn’t special. If you’re already at 6.5%–7% or higher, refinancing to ~7% doesn’t cost you the “repricing penalty,” because there’s no cheap balance to give up. Now the cash-out is just a straightforward way to borrow at a fixed rate.
- You want rate certainty on a large balance. A cash-out is typically fixed for the life of the loan. If you’re borrowing a lot and will carry it for years, locking the rate can be worth paying more than a HELOC would cost today.
- You’re consolidating and want one payment. Rolling higher-rate debt into a single fixed mortgage payment can simplify your life — though if you’re doing this to clear credit cards, it’s worth reading up on payoff strategy first; I’ve written about the debt snowball versus avalanche approaches and when each makes sense.
If your existing rate is already near market and you’re mainly deciding whether refinancing is worth the closing costs at all, that’s a slightly different question — the refinance break-even math is the tool for it.
How much equity can you actually tap?
Usually up to about 80% of your home’s value, counting your existing mortgage — a limit lenders call combined loan-to-value, or CLTV. Some lenders stretch to 85% or higher for strong credit, but 80% is the common cap for either option.
Here’s the arithmetic. Take your home’s value, multiply by the cap, then subtract what you still owe:
- Home value: $500,000
- 80% CLTV cap: $400,000 in total allowed debt
- Existing mortgage: –$280,000
- Room to borrow: about $120,000
That ceiling applies whether you go the HELOC or cash-out route, and it’s before the lender looks at your income and credit to decide how much of it you actually qualify for. So the real question is rarely “can I get to my equity” — it’s “which method lets me get to it without wrecking the rate I already have.” Confirm your lender’s specific CLTV cap; it isn’t standardized.
Is the interest tax-deductible?
Only if you use the money to improve the home itself. IRS Publication 936 states that interest on a home equity loan or line of credit is deductible only if the borrowed funds are used to buy, build, or substantially improve the home that secures the loan.
Use the cash for a kitchen remodel or an addition, and the interest may be deductible (subject to the overall mortgage-interest limits and whether you itemize). Use it to pay off credit cards, buy a car, or cover tuition, and Pub 936 is explicit: you “can no longer deduct the interest… to the extent the loan proceeds weren’t used to buy, build, or substantially improve your home,” no matter when the loan was taken out. This applies to both a HELOC and a cash-out refinance.
I’m deliberately not going further than what the publication says, because the interaction with itemizing, the mortgage-interest cap, and your specific return is genuinely a tax preparer’s job. If a deduction is part of why you’re doing this, confirm it with a tax professional or straight from irs.gov before you count on it.
So which should you choose?
If you have a low mortgage rate and you’re borrowing a modest amount you can repay in a reasonable time, a HELOC usually costs less because it leaves that rate alone. If your existing rate is already near today’s, or you want a large balance locked at a fixed rate, a cash-out refinance can be the better structure. The break point is your current rate versus today’s, and how long you’ll carry the new balance.
Rather than eyeball it, put your real numbers in and see the two side by side. Our HELOC vs cash-out refinance calculator lets you enter your balance, your current rate, how much you need, and today’s rates, and shows you the payment and interest difference for your own situation — including the repricing effect this whole article is about.
And if you’re still working through the bigger housing-cost picture, how much house you can actually afford walks through the payment math from the other direction.
Verified as of September 26, 2026: the 30-year fixed average of 7.03% (Freddie Mac PMMS, week of September 24, 2026); the prime rate of 7.00% (effective September 17, 2026); the ~80% combined loan-to-value cap most lenders use; and the home-equity interest deductibility rule (IRS Publication 936 — deductible only if the funds buy, build, or substantially improve the home). Rates and rules change; confirm current figures with your lender and, for taxes, at irs.gov before you act. This article contains no affiliate or sponsored links.
Sources
- Freddie Mac, Primary Mortgage Market Survey (PMMS): https://www.freddiemac.com/pmms — 30-year fixed 7.03%, 15-year fixed 6.42%, week of September 24, 2026.
- Wall Street Journal prime rate as posted by Commerce Bank: https://www.commercebank.com/about-us/prime-rate-update — 7.00%, effective September 17, 2026.
- IRS Publication 936, Home Mortgage Interest Deduction: https://www.irs.gov/publications/p936 — home equity interest deductible only if used to buy, build, or substantially improve the securing home.
- The Mortgage Reports, maximum HELOC amount / CLTV limits: https://themortgagereports.com/96211/maximum-heloc-amount — typical ~80% (up to 85%+) combined loan-to-value caps.