Home Equity Line of Credit
Last reviewed: May 2026
A HELOC (Home Equity Line of Credit) calculator estimates how much you can borrow against your home equity and what your monthly payments will be. A HELOC works like a credit card secured by your home — you draw funds as needed during a "draw period" (typically 10 years), paying only interest on the amount used. After the draw period, you enter the "repayment period" (10–20 years) where you repay both principal and interest. HELOCs typically carry variable interest rates tied to the prime rate.1
Most lenders allow you to borrow up to 80–85% of your home's value minus your outstanding mortgage balance. This is your available equity.
| Home Value | Mortgage Balance | Equity | Max HELOC (80% LTV) |
|---|---|---|---|
| $400,000 | $280,000 | $120,000 | $40,000 |
| $400,000 | $200,000 | $200,000 | $120,000 |
| $500,000 | $300,000 | $200,000 | $100,000 |
| $500,000 | $200,000 | $300,000 | $200,000 |
Formula: (Home Value × 0.80) − Mortgage Balance = Max HELOC. Some lenders go to 85% or 90% LTV.
A HELOC is a revolving line of credit with variable rates — best for ongoing or uncertain expenses. A home equity loan is a lump sum at a fixed rate — best for known, one-time costs. A cash-out refinance replaces your entire mortgage with a larger one — best when you can also lower your mortgage rate. Compare all three with our HELOC vs Cash-Out Refi Calculator.2
Most HELOCs carry variable rates tied to the prime rate plus a margin (typically prime + 0.5% to prime + 2%). When the Fed raises rates, your HELOC payment increases immediately. A $100,000 balance at prime + 1% costs $625/month at 6.5% prime, but $792/month at 8.5% prime — a $167/month increase. Some HELOCs offer fixed-rate conversion options that lock in a rate on a portion of the balance, providing protection against rate increases.3
Good uses: Home improvements that increase property value, debt consolidation from higher-rate credit cards (if you won't re-accumulate the debt), emergency reserves, or funding education. Bad uses: Discretionary spending, vacations, depreciating assets (cars, electronics), or anything that doesn't build long-term value. A HELOC puts your home at risk — defaulting means potential foreclosure. Use borrowed equity only for purposes that generate financial return.4
HELOCs carry variable interest rates tied to the prime rate (currently around 8.5%), with most lenders adding a margin of 0.5-2% based on creditworthiness and loan-to-value ratio. When the Federal Reserve raises rates, HELOC payments increase directly — a $100,000 balance at prime + 1% would have cost $550/month at a 5.5% rate in 2021 but $792/month at 9.5% in 2024, a 44% increase. Borrowers can mitigate rate risk by drawing only what they need (you only pay interest on the amount drawn, not the credit line), making principal payments during the draw period to reduce the balance before rates rise further, or converting some or all of the balance to a fixed-rate option offered by many lenders. Some lenders offer introductory rate discounts (0.25-1.0% below standard pricing for 6-12 months) that make initial borrowing cheaper but revert to full pricing afterward.
| Feature | HELOC | Home Equity Loan |
|---|---|---|
| Rate type | Variable (typically prime + margin) | Fixed for entire term |
| Disbursement | Draw as needed during draw period | Lump sum at closing |
| Payment during draw | Interest-only option available | Full principal + interest |
| Best for | Ongoing projects, emergency access, uncertain costs | Known one-time expense, rate certainty |
| Risk | Rate increases, payment shock at repayment | Higher initial payments, prepayment penalties possible |
HELOCs are ideal when you need flexible access to funds over time — home renovations that span months, ongoing education expenses, or a financial safety net. Home equity loans work better for defined, one-time expenses like debt consolidation at a known fixed rate, a major single purchase, or when locking in a favorable rate environment. For comprehensive mortgage and equity analysis, see our Mortgage Calculator and Home Affordability Calculator.
Under the Tax Cuts and Jobs Act (TCJA), interest on HELOCs is only deductible if the funds are used to "buy, build, or substantially improve" the home securing the loan. Using a HELOC for a kitchen renovation, room addition, or roof replacement qualifies for the interest deduction, while using it for debt consolidation, education expenses, or a vacation does not. The combined mortgage and HELOC balance eligible for interest deduction is capped at $750,000 ($375,000 for married filing separately). For homeowners with significant equity, the tax benefit can be substantial — at a 24% marginal tax rate, deducting $5,000 in HELOC interest saves $1,200 in taxes, effectively reducing the after-tax borrowing cost by nearly a quarter. Maintaining records of how HELOC funds are spent is essential for claiming the deduction and defending it against potential IRS scrutiny.
The most significant HELOC risk is payment shock when the draw period (typically 5-10 years) ends and the repayment period (10-20 years) begins. During the draw period, many borrowers make interest-only payments — a $150,000 balance at 9% costs approximately $1,125/month in interest only. When repayment begins, the fully amortized payment including principal jumps to approximately $1,350-$1,800/month depending on the repayment term. Borrowers who have only made interest-only payments during the draw period face this increase with no reduction in their balance. Strategic management includes making principal payments during the draw period to reduce the eventual repayment shock, avoiding drawing down the full credit line, maintaining a separate emergency fund rather than treating the HELOC as your emergency reserve (because access can be frozen if home values decline or your financial situation changes), and considering refinancing into a fixed-rate home equity loan before the draw period ends if rates are favorable. Lenders can freeze or reduce HELOC credit lines if property values decline, your credit score drops, or economic conditions deteriorate — as many homeowners discovered during the 2008 financial crisis when banks froze millions of HELOCs without warning.
→ Only borrow what you need. A HELOC is a credit line, not a savings account. Drawing the maximum puts your home at unnecessary risk.
→ Plan for rate increases. Variable rates can rise quickly. Budget for payments at 2–3% above today's rate to avoid payment shock.
→ Prepare for the repayment period. The jump from interest-only to full amortization can double your payment. Start making principal payments during the draw period to smooth the transition.
→ Use for value-building purposes only. Home improvements with strong ROI, debt consolidation (if disciplined), or business investment — not vacations or depreciating assets.
See also: HELOC vs Cash-Out Refi · Home Equity · Mortgage Calculator · Refinance Calculator
→ HELOCs have two phases — understand both before signing. The draw period (typically 10 years) allows interest-only payments on what you've borrowed. The repayment period (10–20 years) requires full principal + interest payments, which can double or triple your monthly obligation. Budget for the repayment phase before committing.
→ Variable rates mean your payment can increase significantly. Most HELOCs are tied to the prime rate. If rates rise 2%, a $100,000 draw goes from $500/month interest-only to $667/month — and that's before repayment begins. Consider whether you could handle a 3–4% rate increase. Compare to fixed-rate options with our HELOC vs Cash-Out Refi Calculator.
→ Your home is the collateral — defaulting means foreclosure. Unlike credit card debt or personal loans, a HELOC is secured by your house. Using home equity for depreciating assets (cars, vacations, consumer goods) puts your home at risk for items that lose value. Home improvements and debt consolidation at lower rates are generally better uses.
→ The 80% combined LTV rule is standard but not universal. If your home is worth $500,000 and you owe $300,000, most lenders cap total borrowing at $400,000 (80% LTV), leaving $100,000 available for a HELOC. Some lenders go to 85% or 90% with higher rates. Build an emergency fund alongside your HELOC — see our Emergency Fund Calculator.
See also: HELOC vs Cash-Out Refi · Home Affordability Calculator · Debt-to-Income Calculator · Emergency Fund Calculator