HELOC vs. Cash-Out Refinance Calculator
Compare the true blended rate of a second mortgage against resetting your first mortgage.
When you need to tap into your home's equity, you face a critical decision: take out a Home Equity Line of Credit (HELOC), a home equity loan (fixed second mortgage), or reset your entire debt with a Cash-Out Refinance. This home equity loan vs cash out refinance calculator projects the blended rate of a second mortgage so you can compare it side-by-side against a full refinance, showing you exactly how to preserve your existing low first mortgage interest rate.
HELOC vs. Refi Scenario Setup
Configure your borrowing options
Existing First Mortgage
BaselineScenario A: HELOC Option
Scenario B: Cash-Out Refi
Note: Refi closing costs (typically 2%-4%) are rolled into your new loan principal, increasing your starting debt balance and compounding interest over 30 years.
4.04%
6.25% refi2.21% lower weighted average coupon*
*Total cost depends on term & fees$2,201
vs $2,180 refiRequires +$22/mo vs 30-yr refi
$148,331
vs $430,670 refiSave $282k in lifetime interest
HELOC vs. Refi: Amortization & Interest Curve
Cumulative Interest Cost Comparison
5-Year Interest Divergence
In the first 5 years alone, resetting your first mortgage rate costs an additional $43,079 in cumulative interest compared to your blended rate strategy.
Lifetime Cost Divergence
Over the full life of the loans, the interest divergence reaches a total savings of $282,339 for the HELOC strategy, demonstrating the immense long-term compounding impact of preserving your low first mortgage rate.
Amortization Schedule
Month-by-month cash flow & balances
Preserve Your Rate Lock
This is a textbook Rate Preservation Play. By keeping your 3.25% first mortgage intact, you avoid resetting your $300k balance to today's higher market rates. Even though the HELOC is at 8.75%, borrowing only what you need saves you $282,339 in lifetime interest.
The 50% Rule of Thumb
If your cash needed exceeds 50% of your existing mortgage balance, a Cash-Out Refinance often becomes more competitive than a second lien.
HELOC vs. Cash-Out Refinance: The Complete Guide
Compare borrowing against your equity without losing your low first mortgage rate.
1The Two Ways to Tap Home Equity
When you need to pull cash out of your home, you have two main paths. The first is a second mortgage (HELOC or home equity loan) that sits on top of your existing first mortgage. The second is a cash-out refinance, which replaces your entire first mortgage with a new, larger loan.
A HELOC (home equity line of credit) is a revolving credit line. You draw money as needed during a draw period, usually 10 years, and pay interest only on what you borrow. After the draw period ends, you enter repayment. For a fair comparison against a 30-year fixed cash-out refinance, this calculator models the secondary loan as a fully drawn, fixed-rate second mortgage. This is how home equity loans work, and it represents the conservative, worst-case cost of borrowing against your equity.
A cash-out refinance replaces your current first mortgage with a brand new loan at today's rates. The new loan is larger than what you owe now, and you receive the difference in cash. Because your entire mortgage balance resets to current market rates, a cash-out refi can be expensive if you are giving up a low rate you locked in years ago.
The Blended Rate: Why It Matters
When you add a second mortgage without touching your first, your true cost of borrowing is not just the HELOC rate. It is the weighted average of both loans. This is called the blended rate:
Blended Rate Formula
Blended Rate = [(First Balance × First Rate) + (Second Balance × Second Rate)] / Total Balance
Example: You owe $300,000 at 3.25% and want to borrow $50,000 at 8%. Your blended rate is not 8%. It is [(300,000 × 0.0325) + (50,000 × 0.08)] / 350,000 = 3.93%. That is the true rate you would compare against a cash-out refinance rate. If current 30-year refi rates are 6.5%, the HELOC path saves you over 2.5% on your entire debt stack.
HELOC vs. Cash-Out Refinance: Head-to-Head
| Feature | HELOC / 2nd Mortgage | Cash-Out Refinance |
|---|---|---|
| Preserves first mortgage rate | Yes | No. Entire balance resets |
| Closing costs | $0 to $500 | 2% to 5% of total loan |
| Monthly payment impact | Adds second payment | One combined payment |
| Typical term for new debt | 10 to 20 years | Resets to 30 years |
| Credit check required | Yes | Yes |
| Appraisal required | Usually | Yes |
When a HELOC Wins
- Your first mortgage rate is low. If you locked in at 3% or 4% and current rates are 6% or higher, keeping your first mortgage untouched saves tens of thousands in interest. The blended rate will almost always be lower than a refi rate.
- The cash you need is small relative to your balance. Borrowing $30,000 on top of a $300,000 mortgage barely moves the blended rate. The refi would reset all $330,000 to a higher rate.
- You want to minimize fees. HELOCs and home equity loans have closing costs of $0 to $500. A cash-out refinance runs 2% to 5% of the total loan amount. On a $400,000 loan, that is $8,000 to $20,000 in fees.
- You want the option to pay off the extra debt faster. With a second mortgage, you can direct extra payments at the higher-rate portion while keeping your low-rate first mortgage intact. This lets you target your payments where they save the most interest. If your goal is to lower your monthly payment instead, consider a mortgage recast.
When a Cash-Out Refinance Wins
- Your current rate is already near or above market rates. If you have a 6.5% mortgage and refi rates are 6.25%, you are not giving up much. Combining everything into one loan at a slightly lower rate can make sense.
- The cash you need is large. If you need to borrow more than 50% of your existing balance, the blended rate can climb high enough that the refi rate looks competitive. The closing costs get spread over a larger loan, making them less painful on a percentage basis.
- You want one monthly payment and a single loan to track. A cash-out refi consolidates everything. One servicer, one payment, one statement. Some people value that simplicity enough to justify a slightly higher rate.
- You need to remove FHA mortgage insurance. If you have an FHA loan with lifetime MIP and you have reached 20% equity, a cash-out refi into a conventional loan kills the mortgage insurance while giving you access to cash. This is one of the few scenarios where the math heavily favors refinancing even if rates are slightly higher.
2HELOC Interest and Taxes
Under current IRS rules, HELOC and home equity loan interest is only tax-deductible if you use the borrowed money to buy, build, or substantially improve the home that secures the loan. If you use HELOC funds to consolidate credit card debt, pay for college, or fund a vacation, the interest is not deductible.
This changed with the Tax Cuts and Jobs Act of 2017. Before that, HELOC interest was deductible regardless of how you used the money, up to $100,000. That is no longer the case. If you are counting on a tax deduction to make the numbers work, confirm with a tax professional that your planned use of the funds qualifies.
3How to Use This Calculator
Enter your current first mortgage balance, interest rate, and remaining term. Then enter the amount of cash you want to borrow and the rate you would pay on a second mortgage or HELOC. The calculator shows:
- Your blended rate when keeping the first mortgage and adding a second lien
- How that blended rate compares to a cash-out refinance at current market rates
- The difference in monthly payments between the two paths
- Total interest paid over the life of both options
- A month-by-month amortization comparison chart
All calculations run in your browser. No loan data gets sent anywhere. Try different cash amounts and second mortgage rates to see where the breakeven point is between keeping your first mortgage and refinancing.
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HELOC vs. Cash-Out Refinance FAQs
Everything you need to know about comparing second liens vs. refinancing.
1What is a HELOC vs. Fixed Second Lien?
A HELOC is a revolving line of credit where you draw funds as needed and often pay interest-only during the draw period. A Fixed Second Lien (Home Equity Loan) provides a lump sum with a fixed interest rate and fully amortizing payments. For a conservative, apples-to-apples comparison against a 30-year Cash-Out Refinance, this calculator models the secondary borrowing as an immediate, fully drawn, fixed-rate second mortgage.
2What is a Cash-Out Refinance?
A cash-out refinance replaces your existing first mortgage with an entirely new, larger mortgage at today's market interest rates. The new loan pays off your old mortgage balance and gives you the difference in cash. Because it resets your entire debt to current rates, it can be costly if you are giving up a low existing rate.
3What is a 'Blended Rate' and why does it matter?
A blended rate is the combined average interest rate of your existing first mortgage and a new second mortgage (HELOC), weighted by their respective balances. It allows you to see the true cost of borrowing additional capital without resetting your primary low-rate mortgage to today's higher market rates.
4When is a HELOC better than a Cash-Out Refinance?
A HELOC is almost always better when you have a very low interest rate on your first mortgage (e.g., 3%-4%) and the new cash you need is relatively small compared to your existing balance. Preserving your first mortgage rate lock saves tens of thousands in lifetime interest.
5When does a Cash-Out Refinance make sense?
A Cash-Out Refi makes sense if your current first mortgage rate is already close to or higher than current market rates, OR if the new cash you need is extremely large (e.g., exceeding 50% of your existing balance). It also stretches the total debt over 30 years, which can provide lower monthly payments if monthly cash flow is your top priority.
6Are closing costs different between the two options?
Yes. HELOCs typically have very low or zero closing costs ($0 to $500). A Cash-Out Refinance involves replacing your entire first mortgage, incurring full closing costs (typically 2%-4% of the total loan amount, or $3,000-$8,000+), which are usually rolled into the new loan balance.
7What is the difference in closing costs between a HELOC and a Refinance?
A HELOC generally requires little to no upfront fees, with closing costs typically ranging from $0 to $500. A Cash-Out Refinance replaces your entire primary mortgage, requiring full closing costs like lender origination fees, title insurance, title search fees, and a new property appraisal, which can range from 2% to 5% of the total loan size (often $3,000 to $8,000+).
8Does a second mortgage impact my first mortgage's low interest rate?
No. Taking out a Home Equity Line of Credit (HELOC) or a Home Equity Loan is a separate, subordinate lien. Your original first mortgage and its low locked-in interest rate remain completely untouched. Conversely, a Cash-Out Refinance completely pays off and replaces your first mortgage, forcing you to reset your entire principal balance to today's current market interest rates.
9Is HELOC interest tax deductible?
According to the IRS, HELOC interest is only tax-deductible if the borrowed funds are used to buy, build, or substantially improve the home that secures the loan. If you use HELOC funds to consolidate personal debts (like credit cards) or pay for a vacation, the interest is not tax-deductible.
10Can I get a HELOC on an investment or rental property?
Yes, but it is much harder than on a primary residence. Lenders typically limit HELOCs on investment properties to lower Loan-to-Value (LTV) limits (typically 70% to 80%), require higher credit scores (usually 720+), charge slightly higher interest rates, and only a select few financial institutions offer them.
11Which is better: a Home Equity Loan or a Cash-Out Refinance?
A Home Equity Loan (a fixed-rate second mortgage) is typically better if you already have a very low interest rate on your primary mortgage and need to borrow a relatively small amount of cash. This allows you to keep your low rate on the bulk of your debt. A Cash-Out Refinance is better if your primary mortgage rate is already close to current market rates, or if you need to borrow a very large sum of cash, as it combines all debt into a single, lower-rate first lien with a reset 30-year term.