HELOC vs. Cash-Out Refi
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) or reset your entire debt with a Cash-Out Refinance. This 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.
Scenario Parameters
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
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.
Frequently Asked Questions
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.