Home Financial Insights Mortgages What Is a HELOC?

Mortgages November 9, 2025 · 8 min read

What Is a HELOC and How Does a Home Equity Line of Credit Work?

A HELOC lets you borrow against the equity in your home as a flexible, revolving line of credit. But its variable rate, draw period, and repayment phase make it very different from a standard mortgage. Here's everything you need to know before opening one.

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What Is a HELOC and How Does a Home Equity Line of Credit Work?

As home values have risen, many homeowners are sitting on substantial equity ??? the difference between what their home is worth and what they still owe on their mortgage. A home equity line of credit (HELOC) is a way to access that equity without selling the home or refinancing the entire mortgage. But it's also a secured loan against your house, which means the stakes are high if things go wrong.

This guide explains exactly how HELOCs work, how to calculate your available equity, what the draw and repayment phases mean for your payments, and when a HELOC makes sense versus when other options are better.

What Is a HELOC?

A HELOC is a revolving line of credit secured by your home. Think of it like a credit card where your home is the collateral ??? you're approved for a maximum credit limit, you can draw funds up to that limit as needed, repay them, and draw again during the draw period. Interest accrues only on what you've actually borrowed, not the full credit limit.

Unlike a home equity loan (which gives you a lump sum at a fixed rate), a HELOC is flexible: you borrow what you need, when you need it, at a variable rate that moves with market interest rates.

How Much Can You Borrow?

Lenders calculate your available HELOC limit based on your home's current value and how much you still owe on your mortgage. Most lenders allow you to borrow up to 80–85% of your home's appraised value, minus what you owe.

Max HELOC = (Home Value × LTV Limit) − Outstanding Mortgage Balance

Example: $400,000 home × 85% = $340,000 − $220,000 mortgage = $120,000 max HELOC

Use our HELOC Calculator to estimate your credit limit and model payment scenarios for different draw amounts.

The Two Phases of a HELOC

A HELOC has two distinct phases that dramatically affect your payments:

Phase 1: The Draw Period (typically 5–10 years)

During the draw period, you can borrow up to your credit limit as needed. Monthly payments are typically interest-only on the outstanding balance ??? which keeps payments low but means you're not reducing principal at all.

Phase 2: The Repayment Period (typically 10–20 years)

When the draw period ends, the line closes ??? you can no longer borrow ??? and your balance converts to a fully amortizing loan. Your monthly payment now includes both principal and interest, and it's calculated to pay off the entire outstanding balance over the repayment period. This often causes a significant payment increase.

PhaseDurationCan Borrow?Payment TypePayment on $80,000 at 8%
Draw period10 yearsYesInterest only~$533/month
Repayment period20 yearsNoPrincipal + interest~$669/month

The payment jump at the end of the draw period surprises many borrowers. Plan for it from day one.

The Payment Shock Risk
If you max out your HELOC during the draw period making interest-only payments, then rates rise and the repayment period begins, your monthly payment could increase substantially. Always model the repayment-phase payment before drawing heavily on a HELOC.

HELOC Interest Rates

HELOC rates are almost always variable, tied to a benchmark rate (most commonly the Prime Rate) plus a margin set by the lender. When the Prime Rate rises, your HELOC rate rises. When it falls, your rate falls.

ComponentExample
Prime Rate (index)8.50%
Lender margin+0.50%
Your HELOC rate9.00%

Some lenders offer rate caps (periodic and lifetime) that limit how much the rate can increase. Ask about these. Some also offer a fixed-rate conversion option that lets you lock in a portion of your balance at a fixed rate ??? useful if rates rise significantly during your draw period.

HELOC vs. Home Equity Loan vs. Cash-Out Refinance

FeatureHELOCHome Equity LoanCash-Out Refinance
Rate typeVariableFixedFixed
DisbursementDraw as neededLump sumLump sum
Best forOngoing or uncertain costsOne-time known expenseReplacing existing mortgage too
Closing costsLow–moderateModerateHigh (full mortgage closing)
Affects primary mortgage?NoNoYes ??? replaces it

When a HELOC Makes Sense

  • Home renovations with uncertain costs ??? Kitchen remodels, additions, and phased projects benefit from drawing as bills arrive rather than borrowing a lump sum upfront.
  • Ongoing expenses over time ??? Tuition paid in installments, business expenses, or medical costs that arrive over months or years.
  • Emergency backup ??? Some homeowners open a HELOC with no balance as a large emergency fund backstop. You pay nothing until you draw ??? just an annual fee in some cases.
  • Debt consolidation at a lower rate ??? If your HELOC rate is significantly lower than high-interest debt, consolidating can make sense. But this converts unsecured debt to debt secured by your home ??? a meaningful risk increase.

When a HELOC Doesn't Make Sense

  • Buying depreciating assets ??? Using your home equity to fund a vacation, car, or luxury purchase means borrowing against your home for a consumable. Risky.
  • When you can't handle rate increases ??? If a 2–3% rate increase would make the payment unmanageable, a fixed-rate home equity loan is safer.
  • When your income is unstable ??? A HELOC secured by your home means a payment default puts your home at risk of foreclosure.
  • When you're close to retirement ??? Adding a 20-year repayment obligation late in your earning years can create cash flow problems in retirement.
Your Home Is the Collateral
Unlike credit card debt (unsecured), a HELOC default can result in foreclosure. This doesn't mean HELOCs are bad ??? but it does mean they deserve more caution than unsecured borrowing. Borrow only what you have a clear plan to repay.

Model Your HELOC Payments

The HELOC Calculator shows your draw-period and repayment-period payments for any draw amount and rate.

HELOC Calculator

Weighing a HELOC vs Selling and Moving?

Sometimes a renovation via HELOC competes with just selling and buying something better. The Rent vs Buy Calculator helps model that decision with real numbers.

Rent vs Buy Calculator
The Bottom Line
A HELOC is a flexible, lower-rate borrowing tool for homeowners with equity ??? best suited for ongoing or variable expenses where a lump sum doesn't fit. The variable rate and two-phase payment structure require careful planning. Calculate the repayment-period payment before drawing heavily, keep your DTI manageable, and never use home equity to fund consumption you can't afford.