HELOC Calculator

Calculate HELOC payments for draw and repayment periods. See max available credit and total interest cost.

By Konstantin Iakovlev · Updated September 2026 · Source: CFPB — Owning a Home

$
$
$
%
years
years

Max HELOC Available

$80,000.00

Interest-Only Payment

$354.17/mo

During draw period

P&I Payment

$433.91/mo

During repayment

HELOC Details

HELOC Amount$50,000.00
Combined LTV73.3%
Draw Period Interest-Only$354.17/mo
Repayment Period P&I$433.91/mo
Interest During Draw Period$42,500.00
Interest During Repayment$54,138.79
Total Interest Paid$96,638.79

HELOC vs Cash-Out Refinance

HELOC Monthly (repayment, plus your current mortgage payment)$433.91/mo
Cash-Out Refi Monthly (new $330,000.00 loan, 7%, 30 yr)$2,195.50/mo
HELOC Total Interest (on the line only)$96,638.79
Cash-Out Refi Total Interest (whole new loan)$460,379.36

A cash-out refinance replaces your current mortgage, so its payment and interest cover the whole balance. The HELOC figures cover only the line of credit; your existing mortgage payment continues on top of them.

Use the HELOC Calculator above to calculate your results. Enter your values and see instant results — all calculations run in your browser.

Disclaimer: This calculator is for informational purposes only and does not constitute tax, financial, or legal advice. Results are estimates based on the information you provide and current rates. Always consult a qualified tax professional or financial advisor for advice specific to your situation.

How It Works

A HELOC calculator answers two related questions: how much you can draw against your home's equity and what the monthly payments are likely to run. Those figures help you weigh whether a line of credit makes sense for a renovation, debt consolidation, or another sizable expense.

Available equity starts with your home's current market value less the outstanding mortgage balance. Lenders then cap the line with their own loan-to-value limit; this calculator allows up to 80% of the home's value minus the mortgage balance and warns you if the amount you ask for is higher. Payments depend on the outstanding balance, the current interest rate, and which phase you're in, whether the interest-only draw period or the repayment period that adds principal on top. For comparison, the calculator also prices a cash-out refinance of the mortgage balance plus the HELOC amount at a fixed 7% over 30 years.

Most HELOCs carry variable rates, so a payment that looks manageable today can climb as rates move. The sharpest jump usually arrives when the interest-only draw period ends and full principal-and-interest payments begin, a shift many borrowers underestimate. Build room for rate increases into your plan, and stop short of drawing the full line so you keep some financial flexibility in reserve.

HELOC Calculation for $450,000 Home with $180,000 Mortgage Balance

  1. 1 Current home value is $450,000 with an outstanding mortgage balance of $180,000, giving you $270,000 in equity before any lender limit.
  2. 2 At the calculator's 80% loan-to-value cap, the maximum line is ($450,000 × 0.80) − $180,000 = $360,000 − $180,000 = $180,000.
  3. 3 You draw $150,000 at 8.25%, the 7.00% prime rate of mid-September 2026 plus a 1.25-point margin, with a 10-year draw period. The interest-only payment is $150,000 × 0.0825 ÷ 12 = $1,031.25 a month, and the combined LTV is ($180,000 + $150,000) ÷ $450,000 = 73.3%.
  4. 4 When the draw period ends, the $150,000 is amortized over 20 years at 8.25%: $1,278.10 a month, $246.85 more than the interest-only payment. If the rate stayed at 8.25%, interest would total $123,750.00 in the draw period and $156,743.63 in repayment, $280,493.63 in all; a variable rate can move that either way.

Source: CFPB — Owning a Home · Last updated: September 2026

Frequently Asked Questions

What is the current HELOC interest rate?
Each lender sets its own HELOC rate. Most HELOCs are variable: the rate is an index, usually the prime rate, plus a margin that depends on your credit score, combined loan-to-value ratio and lender. The prime rate has been 7.00% since September 17, 2026 (Federal Reserve H.15), so a line priced at prime plus 1 point would currently charge 8.00%.
How does a HELOC draw period work?
During the draw period (typically 10 years), you can borrow up to your credit limit and usually pay only interest. After the draw period ends, you enter the repayment period (10-20 years) and must pay principal plus interest.
Is HELOC interest tax deductible?
HELOC interest is tax deductible only if you itemize and the funds are used to buy, build, or substantially improve the home securing the loan, and then only on the first $750,000 ($375,000 if married filing separately) of your combined mortgage debt; P.L. 119-21 made these limits permanent in 2025. Using HELOC funds for other purposes like debt consolidation is not deductible.

You might also need

Mortgage Calculator 2026 — Payment, Amortization & PMI

Calculate your monthly mortgage payment with taxes, insurance, PMI, and HOA. Free, instant results at the interest rate you enter.

FHA Loan Calculator 2026 — MIP, Down Payment & Limits

Calculate FHA loan payments including upfront MIP (1.75%) and annual MIP premiums. See when MIP drops off. Free, instant results based on 2026 FHA limits.

Home Affordability Calculator — How Much House Can You Afford?

Find out how much house you can afford based on income, debts, down payment, and the mortgage rate you enter. Free, instant results with DTI ratio breakdown.