HELOC Calculator: How Much Home Equity Can You Borrow?

A HELOC — Home Equity Line of Credit — lets you borrow against the equity you've built in your home. Unlike a home equity loan (a lump sum), a HELOC is a revolving credit line: draw what you need, when you need it, and pay interest only on what you've borrowed. It's flexible, often cheaper than personal loans, and frequently used for home improvements, debt consolidation, or major expenses. But a HELOC has a structure that trips up many borrowers: the draw period (typically 5–10 years) and the repayment period (typically 10–20 years). During the draw period, you often pay interest only — which means your monthly payment can be deceptively low. When the repayment period begins, you must pay both principal and interest on the full balance, and that payment can jump dramatically. Borrowers who maxed their credit line during the draw period sometimes face payment shock when repayment begins. Most lenders allow you to borrow up to 80–85% of your home's current value, minus your existing mortgage balance. This calculator determines your maximum borrowing limit based on your home value, current mortgage balance, and the lender's combined loan-to-value (CLTV) limit. It also shows your draw period payment (interest only) vs. repayment payment (amortized), and total interest across the full lifecycle. Know exactly what you're getting into before you open the line.