HELOC Payment Calculator: Draw, Repayment, and True Cost Explained

A Home Equity Line of Credit (HELOC) is one of the cheapest sources of borrowed money for homeowners with equity — and one of the easiest products to misunderstand. The teaser-rate first year, the interest-only draw period, the variable-rate adjustments, and the eventual jump to fully amortizing payments combine into a financial instrument where today’s affordability tells you very little about year 11’s affordability.

This guide explains how HELOCs actually work in 2026, the difference between a HELOC and a home equity loan or cash-out refinance, and the best free HELOC calculators and lender comparison platforms — so you can model both the draw and repayment phases before opening a line.

How HELOCs differ from a cash-out refinance

Three home-equity products share the goal of tapping equity but differ in mechanics:

HELOC (Home Equity Line of Credit)

A revolving line of credit secured by your home. You’re approved for a maximum amount, but you only owe interest on what you’ve drawn. During the draw period (typically 10 years), payments are interest-only, and you can re-draw repaid balances. Variable rate (typically Prime + margin). After the draw period ends, you enter a repayment period (10–20 years) of fully amortizing P&I payments.

Best for: ongoing or staged expenses (multi-year home renovation, college tuition over 4 years, emergency reserve), borrowers who want flexibility.

Home Equity Loan (HEL)

A fixed-amount second mortgage. You receive a lump sum at closing and start amortizing payments immediately at a fixed rate. No draw period, no variable rate, no flexibility.

Best for: known-amount one-time expenses (debt consolidation, major single project), borrowers who want payment certainty.

Cash-Out Refinance

Replaces your existing mortgage with a larger one; you pocket the difference. Single payment combining old and new mortgage debt. Fixed or adjustable rate.

Best for: larger amounts, tapping equity while also lowering rate (if current mortgage rate > new rate), simplifying to one mortgage.

The calculator focuses on HELOCs but shows comparison output against HEL and cash-out for the same equity tap.

What a HELOC calculator should model

Three phases need separate math:

Draw period (years 1–10)

Interest-only payments on the drawn balance:

Monthly payment = Drawn balance × (APR / 12)

Variable rate adjusts monthly or quarterly based on Prime rate movements. Most HELOCs have rate caps (lifetime cap typically 5–6% above the start rate; periodic adjustment caps).

Transition (end of year 10)

The moment when:

• Draw period ends (no more re-borrowing)
• Outstanding balance becomes the principal
• Repayment period begins
• Monthly payment shifts from interest-only to fully amortizing

This is where payment shock happens. A $100K balance at 8% APR was an $667/month interest-only payment. The same balance amortizing over 20 years at 8% becomes a $836/month P&I payment — a 25% jump. If rates have risen during the draw period, the shock is larger.

Repayment period (years 11–30)

Standard amortization. Variable rate may continue, with each rate change recalculating the payment.

The calculator runs all three phases and shows the year-by-year payment schedule, total interest paid, and worst-case payment shock under variable-rate stress scenarios.

Tool usage guide: draw phase + repayment phase

1. Enter your home value and current mortgage balance

Combined LTV calculation depends on these. Home value: realistic estimate (Zillow, Redfin, recent appraisal). Current mortgage balance: your most recent statement.

2. Enter the line size and your expected draw amount

The line size is the total available credit. The draw amount is what you actually plan to use. They can be the same (use the full line) or different (open a $100K line, plan to use $40K initially).

3. Enter the starting APR

Most HELOCs are quoted as “Prime + X” where X is your margin (typically 0–3%). In April 2026, with Prime at ~7.5%, a “Prime + 0.5%” HELOC has a starting APR of 8.0%. Some products offer introductory rates (e.g., 6.99% for the first 12 months) — the calculator can model this.

4. Enter draw and repayment periods

Standard: 10-year draw, 20-year repayment (30-year total). Custom configurations possible.

5. Enter your draw schedule

If you’ll use the HELOC in chunks (e.g., $30K for kitchen, $20K for bathroom in year 2, $25K for college tuition in year 4), enter the schedule. Otherwise, the calculator assumes the full draw amount is taken in month 1.

6. Stress-test variable rates

Three scenarios you should run:

• Base case: rate stays where it is today
• +1% case: rates rise by 1 percentage point and hold
• +3% case: rates rise by 3 percentage points (recession-rebound scenario)

The output shows monthly payment under each scenario for the draw and repayment phases.

7. Read the comparison

The calculator surfaces:

• Total interest over 30 years (base case)
• Total interest at +3% rate stress
• Payment shock at end of draw period
• Comparison to home equity loan with same amount fixed
• Comparison to cash-out refinance economics

Real-world example: home renovation HELOC

The Hendersons want to renovate their kitchen and master bath, total budget $80,000. They have $400K equity in a $750K home (53% LTV).

HELOC offer:

• Line size: $100K (they want flexibility)
• Starting APR: 8.5% (Prime + 1.0%, with current Prime at 7.5%)
• Draw period: 10 years (interest-only)
• Repayment: 20 years
• Draw amount: $80K (taken in months 2 and 5)

Output:

Draw period (years 1–10):

• Monthly interest: $80,000 × 8.5% / 12 = $567/month
• Total interest paid in draw period (assuming rates stay flat): $68,000
• Maximum equity tapped: $80K balance, 64% CLTV

Repayment period (years 11–30, $80K amortizing at 8.5% over 20 years):

• Monthly P&I: $695/month (vs $567 interest-only)
• Payment shock: +23%
• Total interest paid in repayment period: $87,000

Total interest over 30 years (rates flat scenario): $155,000 on a $80K loan.

Stress test +3%:

• Repayment phase APR: 11.5%
• Monthly P&I in year 11: ~$852 (50% higher than initial draw payment)
• Total lifetime interest: ~$200K

Comparison to a $80K Home Equity Loan at 8.0% fixed for 20 years:

• Monthly P&I from day 1: $669
• Total interest: $80,560

For renovations like this, the HEL is often the better choice because: 1) you know the amount upfront, 2) fixed rate eliminates rate-shock risk, 3) lower lifetime interest, 4) forced amortization builds equity from year 1.

The calculator surfaces this trade-off directly.

Benefits: avoid payment shock, plan major projects

Visualize payment shock. Most HELOC borrowers don’t think about year 11 until year 11. The calculator shows it on day 1. If the post-draw payment doesn’t fit your projected income, the line size is too large.

Compare HELOC to alternatives. HELOC vs HEL vs cash-out refi vs personal loan vs 0% credit card balance transfer. Different products win for different situations; the calculator runs all five.

Plan staged draws. For multi-year projects, the staged-draw mode shows interest accrual based on actual draw timing, not the full line size. You only pay interest on what you’ve drawn.

Stress-test rates. Variable-rate borrowers face rate-rise risk. Showing what happens at +1%, +2%, +3% lets you decide whether you can tolerate that scenario.

Right-size the line. A $200K line “just in case” sounds prudent but increases your overall debt-to-income ratio (lenders count the full line, not the drawn balance, in some calculations) and may reduce future borrowing capacity. The calculator shows the trade-off.

Use cases

Home renovation

The classic HELOC use. Stage draws as projects complete; pay interest-only during construction; refinance to a HEL or amortize after.

Debt consolidation

Use HELOC to pay off high-APR credit cards. Math works only if you don’t re-charge the cards. Discipline gating: cut up the cards, freeze them, or ask a partner to hold them.

Tuition

Year 1–4 of college tuition staged across the draw period. Payments are interest-only while in school; principal paydown begins after graduation.

Emergency fund / standby liquidity

Open the line, never draw it, pay nothing (some HELOCs have annual fees, some don’t). When emergency hits, you have instant access to large liquidity at home-equity rates rather than 27% credit card APR.

Bridge financing

Buying a new home before selling the old one? HELOC on the old home funds the new home’s down payment. Repay when the old home sells.

Investment property purchase

Use HELOC on primary residence to fund down payment on a rental property. Risky if the rental doesn’t cash flow; powerful if it does.

Self-employed cash-flow management

Lumpy income (consultants, real estate agents, contractors) benefits from a HELOC as a cash-flow smoother. Draw during dry months, pay back during peaks.

CLTV and how lenders cap your line

Combined Loan-to-Value (CLTV) = (current mortgage balance + new HELOC line) / home value.

Most lenders cap CLTV at 80–90%. Examples:

To qualify for the higher CLTV tiers, you need stronger credit (740+), stable income, and lower DTI. CLTV above 90% is rare in 2026 except through niche lenders at premium rates.

Variable rate risk and how to stress-test

HELOC rates are tied to Prime. When the Federal Reserve raises rates, Prime moves; your HELOC rate moves with it. The 2022–2023 cycle saw Prime rise from 3.25% to 8.5% — that’s a 5.25 percentage point increase over 18 months. A $100K HELOC borrower’s interest-only payment rose from ~$300/month to ~$700/month over that period.

Stress-testing approaches:

Worst-case modeling. Run the calculator with rates 3–5 percentage points above today’s. If you can still afford the payment, you’re well-positioned. If not, you’re taking on rate risk you may not be able to absorb.

Convert-to-fixed option. Many HELOC products allow you to convert all or part of your drawn balance to a fixed-rate “tranche” at any time. If rates start rising and you have a large balance, convert before the next hike.

Rate cap awareness. Federal regulation requires HELOCs to have a lifetime cap (often 18%, sometimes 5% above start rate). Know yours.

Refinance to HEL or fixed-rate option. If rates are clearly rising and you have substantial drawn balance, refinancing into a fixed-rate home equity loan locks in the cost.

Pro tips

Open the line when you don’t need it. Approval is easier when you have stable income, no recent credit pulls, and no urgent need. Apply during a calm financial period; let the line sit unused until you need it.

Watch annual fees. Some HELOCs charge $50–$100 annual fees on undrawn lines; others have no fees. The fee-free options are worth shopping for.

Avoid early-closure fees. Many HELOCs have a “close within 3 years and pay $300” clause to recoup the lender’s setup costs. Read the fine print before opening.

Don’t stack multiple HELOCs. Two HELOCs on the same property is rare and usually a sign of borrower distress. Lenders see this in your credit report and price accordingly.

Refinance the old HELOC instead of opening new. If you’ve had a HELOC for 5 years and your balance is paid down, refinancing the existing line at a new rate often beats opening a fresh one (no closing costs, faster).

Don’t use HELOC for depreciating assets. Cars, vacations, weddings — all are bad uses of home-equity debt. The asset depreciates while the debt persists; you’re permanently underwater on the spend.

Prepay aggressively in the draw period. During the draw period, anything beyond the interest-only payment goes straight to principal. Prepay $100–$200/month on top of interest and you’ll significantly reduce the eventual amortization shock.

Tax-deduction trap awareness. Pre-2017 rules allowed HELOC interest deduction regardless of use. Post-2017, only “buy, build, or substantially improve” use qualifies. Document your use carefully.

Best HELOC calculators and lenders (2026)

A complete HELOC workflow uses a calculator + a home value estimator + a lender comparison platform.

Best free HELOC calculators

• Bankrate HELOC Payment Calculator — Models draw and repayment phases.
• NerdWallet HELOC Calculator — Clean UX with stress-test scenarios.
• Discover HELOC Calculator — Tied to Discover’s HELOC offering but free to use.
• Zillow HELOC Calculator — Combined with Zestimate home value.
• CFPB Home Equity Tool — Official US guidance.

Best HELOC and home-equity lenders

• Figure — Fast digital HELOC, often closes in 5 days.
• Spring EQ — Specialist in HELOCs and home equity loans.
• Discover Home Loans — Established lender, no closing costs on home equity loans.
• Aven — HELOC delivered as a credit card.
• Rocket Mortgage HELOC — Major lender’s HELOC offering.
• Bank of America HELOC — Big-bank HELOC with relationship discounts.
• U.S. Bank HELOC — Established HELOC lender.

Home equity unlock alternatives (no monthly payment)

• Hometap — Equity-share product (you sell a piece of future appreciation).
• Point — Similar equity-share alternative.
• Unison — Co-investment alternative to HELOC.

Home value and equity tools

• Zillow Zestimate — Most-used free home value estimate.
• Redfin Estimate — Often more accurate than Zillow in active markets.
• Realtor.com My Home — Free home value tracking.
• FHFA House Price Index Calculator — Official US HPI for tracking appreciation.

Lender comparison platforms

• LendingTree HELOC — Multi-lender HELOC quotes.
• Credible HELOC — Compare without affecting credit score.

Educational resources

• CFPB — What’s the difference between a home equity loan and a HELOC? — Official US guidance.
• IRS Publication 936 — Home Mortgage Interest — Official tax-deduction rules for HELOC interest.

Frequently asked questions

How is a HELOC payment calculated?

During the draw period (typically 10 years), payments are interest-only on the balance you’ve actually drawn. Formula: balance × (APR / 12). During the repayment period (typically 10–20 years), payments amortize like a regular loan. The shift from interest-only to amortizing payment often increases the monthly payment 50–100%, called payment shock.

What is the typical HELOC draw period?

10 years is standard. Some lenders offer 5- or 7-year draw periods. Federal regulations cap the total HELOC term (draw + repayment) at 30 years for most products.

How much HELOC can I get with $200k equity?

Lenders typically allow combined loan-to-value (CLTV) up to 80–90% of home value. If you have $200K equity in a $500K home (60% LTV current), most lenders will let you borrow up to $200K–$250K via HELOC.

Is HELOC interest still tax deductible?

Only if the loan proceeds are used to “buy, build, or substantially improve” the home that secures the HELOC.

HELOC vs Home Equity Loan — which is better?

HELOC for flexible draws and lower initial payments. HEL for fixed-amount one-time expenses and rate certainty. The right choice depends on the use case.

Can I lose my home if I default on a HELOC?

Yes. A HELOC is secured by your home; default can lead to foreclosure. Treat HELOC debt like first mortgage debt — pay before any unsecured debt.

How long does HELOC approval take?

3–6 weeks at most lenders. Some online lenders (Figure, Spring EQ) close in 5–10 business days for qualified borrowers.

Are there closing costs on a HELOC?

Lower than a refinance: $0–$2,500 typically. Some lenders waive closing costs if you keep the line open for 3+ years.

What happens if I sell my house?

The HELOC must be paid off at closing from sale proceeds, just like the first mortgage. The HELOC is a lien against the property; clearing the lien is required to transfer title.

A HELOC is a powerful tool when used carefully and a financial trap when used carelessly. Run the math, stress-test the rates, and make sure the year-11 payment is one you can afford even if rates rise.