HELOC vs Cash-Out Refinance: Should You Keep Your Low Rate?

The dilemma every homeowner with a low rate faces

You bought or refinanced when rates were historically low. Now your first mortgage sits at 3% or 4%, and you need cash — for renovations, debt payoff, an investment property, or a child's tuition.

The problem: pulling cash out of your equity usually means replacing your entire loan with a new one at today's higher rate. That low rate you worked so hard to lock in? Gone.

There is another path. Instead of refinancing the whole loan, you can keep your first mortgage untouched and add a second lien — a HELOC or HELOAN — on top of it. The new second mortgage carries a higher rate, but it only applies to the cash you pull out, not your entire balance.

The question is whether the math actually works in your favor. That's what this article breaks down.

What is a HELOC?

A HELOC (Home Equity Line of Credit) is a revolving line of credit secured by your home's equity. It works like a credit card with a much lower rate:

• Draw period (usually 10 years): you can borrow and repay repeatedly, interest-only payments are common
• Repayment period (usually 20 years): the line closes and you pay back what you owe, principal + interest
• Rate: typically variable, tied to the prime rate plus a margin
• You only pay interest on what you draw, not the full credit limit

A HELOC is best when you need flexibility — you might draw for a renovation, repay it, then draw again for tuition next year.

What is a HELOAN?

A HELOAN (Home Equity Loan) is a fixed second mortgage. You receive the full amount upfront as a lump sum and repay it with fixed monthly payments over a set term (commonly 15-30 years).

• Rate: fixed for the life of the loan
• Payment: predictable, same amount every month
• You receive the entire amount at once

A HELOAN is best when you need a specific, known amount all at once — like a major renovation or debt consolidation — and you want payment certainty.

What is a Cash-Out Refinance?

A cash-out refinance replaces your existing first mortgage with a new, larger first mortgage. The difference between your old balance and the new loan amount comes to you as cash at closing.

• Your old rate and loan are gone — the entire new balance carries today's rate
• You have one loan, one payment, one lender
• Closing costs are similar to a purchase mortgage (2-5% of the loan amount)

The blended rate: the key number most people miss

Here's where the decision gets interesting. When you keep your first mortgage and add a HELOC, you don't pay the HELOC rate on your whole debt — you pay it only on the new cash. Your first mortgage keeps its low rate on its balance.

The blended (combined) rate is the weighted average of both loans:

Blended Rate = (Balance 1 × Rate 1 + Balance 2 × Rate 2) / (Balance 1 + Balance 2)

Example

• Current first mortgage: $250,000 at 3.5%
• Cash needed: $50,000
• HELOC rate: 8.5%
• Cash-out refinance rate: 7.0%

Blended rate (HELOC path):

(250,000 × 3.5% + 50,000 × 8.5%) / 300,000
= (8,750 + 4,250) / 300,000
= 4.33%

Your combined rate across both loans is 4.33% — well below the 7.0% you'd pay if you refinanced everything. Even though the HELOC itself is at 8.5%, it only covers a sixth of your total debt, so its high rate is diluted by your cheap first mortgage.

This is the core insight: when your first mortgage rate is much lower than today's refinance rate, the blended rate of keeping it + adding a HELOC often beats a full cash-out refinance.

When the HELOC / HELOAN path wins

• Your first mortgage rate is significantly below today's rate (a 2%+ gap makes the blended rate hard to beat)
• You need a smaller amount of cash relative to your balance (the smaller the HELOC, the more your low first rate dominates the blend)
• You want flexibility to draw and repay over time (HELOC)
• You want to preserve the long-term interest savings of your low-rate first mortgage
• You plan to pay the HELOC off relatively quickly (reducing the impact of its higher rate)

When the cash-out refinance wins

• Your first mortgage rate is close to today's rate (the blended rate offers little advantage)
• You need a large amount of cash (the HELOC's higher rate starts dominating the blend)
• You want a single, simple payment with one lender
• You want a fixed rate on everything (HELOCs are usually variable)
• Your current first mortgage is near the end of its term anyway
• You can get a cash-out rate that beats your blended rate

The LTV factor you can't ignore

n Both options depend on your loan-to-value (LTV) ratio — how much you owe against the home's value. Most lenders cap the combined LTV (first mortgage + HELOC) at 80% to 90%.

If your home is worth $400,000 and you owe $250,000, your current LTV is 62.5%. Pulling out $50,000 brings your combined LTV to 75% — within most lenders' limits. But if you owe $350,000 on that same home, you're at 87.5% after the cash-out, which may limit your options or require a higher rate.

The more equity you have, the more room you have to maneuver.

The variable-rate risk of HELOCs

Most HELOCs have variable rates tied to the prime rate. If rates rise, your HELOC payment rises with them. This is the main risk of the HELOC path: your blended rate is low today, but the HELOC portion can climb.

If you're concerned about rising rates, a HELOAN (fixed-rate second mortgage) gives you the same keep-your-first-mortgage advantage with a fixed payment — though usually at a slightly higher rate than a HELOC's starting rate.

Closing costs: a real difference

• HELOC / HELOAN: closing costs are typically low or even zero — many lenders waive them if you keep the line open for a minimum period (often 1-3 years)
• Cash-out refinance: closing costs run 2-5% of the loan amount, similar to a purchase. On a $300,000 loan, that's $6,000 to $15,000

This matters. If your blended-rate savings are small, the closing costs of a cash-out refinance can eat the advantage. If the blended rate saves you significantly, the closing costs are a minor factor.

How to decide: a quick framework

1. Calculate your blended rate — use our HELOC vs Cash-Out calculator to see it instantly
2. Compare it to the cash-out refinance rate — if the blended rate is more than 0.5% lower, the HELOC path usually wins
3. Check your LTV — make sure you have enough equity for the cash you need
4. Consider rate risk — if you can't tolerate a variable payment, lean HELOAN or cash-out refi
5. Factor in closing costs — low for HELOC, significant for cash-out refi
6. Think about how long you'll keep the loan — the longer you hold, the more the interest savings matter

The bottom line

There is no universal answer. The right choice depends on three numbers: your current rate, today's rates, and how much cash you need relative to your balance.

When your first mortgage rate is much lower than today's rates and you need a modest amount of cash, keeping that low rate with a HELOC or HELOAN is often the smartest move you can make. When the gap is small or you need a large amount, a cash-out refinance may be simpler and cheaper.

Run the numbers. Then talk to a licensed mortgage professional who can show you real quotes for both paths — because the only way to know for sure is to compare actual offers on your actual situation.

---

Want to see your blended rate and compare both options side by side? Try our free HELOC vs Cash-Out Refinance calculator.