HELOC Calculator
Estimate your available HELOC credit line and interest-only payments during the draw period.
Enter your numbers and select Calculate to see results.
About This Calculator
A Home Equity Line of Credit (HELOC) lets you borrow against your home's equity as needed, up to a set credit limit, typically at a variable interest rate. This calculator estimates your available credit line based on your home's value and mortgage balance, and shows an estimated interest-only payment during the draw period for a given amount drawn.
How This Is Calculated
Available Credit = (Home Value × Max LTV%) − Mortgage Balance
- Interest-Only Payment
- — Amount Drawn × (HELOC Rate ÷ 12), typical during the draw period
A $450,000 home with a $280,000 mortgage and an 80% LTV limit has about $80,000 in available credit. Drawing $40,000 at 8.5% costs roughly $283/month in interest-only payments.
Assumptions
- Most HELOCs charge interest-only payments during an initial draw period (often 10 years), then require principal and interest repayment.
- HELOC rates are typically variable, tied to an index like the prime rate — your actual payment will fluctuate.
- Actual credit line depends on lender underwriting, credit score, and income, not just home equity.
Frequently Asked Questions
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Last updated January 15, 2026. Results are estimates for informational purposes only — read our disclaimer.