HELOC Calculator — Home Equity Line of Credit

Enter your home value and mortgage balance — see your maximum HELOC credit line, draw period payments, and full repayment schedule at current rates.

How a HELOC Works

  • A HELOC lets you borrow against your home equity up to a set credit limit — typically 80%–85% of your home's value minus your remaining mortgage balance. It functions like a credit card secured by your home.
  • During the draw period (usually 10 years) you can borrow and repay repeatedly, often making interest-only payments. The repayment period (typically 10–20 years) then requires full principal and interest payments.
  • HELOCs carry variable interest rates tied to the prime rate, which means your payment can change month to month. A home equity loan is the fixed-rate alternative if payment predictability matters more.

Calculation details

Methodology

Available credit equals the selected combined loan-to-value percentage multiplied by home value, minus the current mortgage balance. The draw-period payment is modeled as interest-only on the selected draw. Repayment uses a standard fixed-payment formula on that draw at the entered draw rate plus repayment margin.

Assumptions and limitations

  • CLTV percentages are illustrative choices, not approval limits or lender commitments.
  • The full selected draw is assumed outstanding throughout the draw period.
  • Rates remain constant within each phase even though most HELOC rates are variable.
  • Appraisal, origination, annual, early-closure, and other fees are excluded.
  • Credit, income, lien position, property eligibility, and underwriting are not evaluated.

Worked example: $80,000 HELOC draw

  • $600,000 home value
  • $350,000 current mortgage
  • 80% selected CLTV
  • $80,000 draw at 8.5%
  • 10-year draw and 20-year repayment at a modeled 9.0%

The modeled credit limit is $130,000. An $80,000 draw produces about $567 monthly interest-only payment, followed by about $720 monthly principal-and-interest payment during repayment.

Actual payments can change with the index, margin, draw activity, fees, and lender terms. Review the HELOC disclosure before borrowing.

Official sources

Frequently Asked Questions

How does a HELOC work?

A HELOC (Home Equity Line of Credit) is a revolving credit line secured by your home's equity. During the draw period (typically 10 years), you can borrow up to your limit, repay it, and borrow again — like a credit card. During the repayment period (typically 10–20 years), you can no longer draw funds and must repay the remaining balance in full principal-and-interest payments.

How much can I borrow with a HELOC?

Most lenders allow you to borrow up to 80%–85% of your home's appraised value, minus your outstanding mortgage balance. If your home is worth $500,000 and you owe $300,000, your maximum HELOC could be ($500,000 × 85%) − $300,000 = $125,000. Your actual approval depends on your credit score, income, and debt-to-income ratio.

What is the current HELOC interest rate?

HELOC rates are variable and tied to the prime rate (which moves with the Federal Reserve's benchmark). When the Fed raises rates, HELOC rates rise; when it cuts rates, HELOCs become cheaper. As of 2025, HELOC rates typically run 1%–2% above prime. Check with your bank or credit union for current offers — rates vary significantly by lender and credit profile.

HELOC vs. home equity loan: what's the difference?

A HELOC is a revolving line with a variable rate — flexible but unpredictable payments. A home equity loan is a fixed lump sum at a fixed rate — predictable payments but less flexibility. HELOCs work best for ongoing projects or expenses where you draw funds over time. Home equity loans work best for one-time large expenses (major renovation, debt consolidation) where you want payment certainty.

How to use this estimate

This calculator is an educational planning tool. Results are based on the figures and assumptions entered by the reader, use standard mortgage mathematics, and are not a loan offer, approval, or substitute for a lender's Loan Estimate. Taxes, insurance, fees, mortgage insurance, and available rates vary by borrower, property, lender, and location.

Review the assumptions, compare more than one scenario, and confirm the final numbers with a licensed mortgage professional before making a financial commitment.