HELOC Calculator

Calculate your Home Equity Line of Credit (HELOC) available credit and payments. See how much you can borrow against your home equity.

This calculator separates two distinct HELOC concepts that are easy to conflate: Available HELOC Credit is purely an equity ceiling (Home Value × Credit Limit % minus Current Mortgage Balance, floored at $0 on line 14) — it never depends on the rate you'd pay or how much you actually plan to draw — while Monthly Payment and Interest-Only Payment are built entirely from Amount to Borrow, the rate, and the repayment period, and never move in response to Home Value, Current Mortgage Balance, or Credit Limit %. Amount to Borrow dominates Monthly Payment: pull it 10% under its default value, then push it 10% over, and Monthly Payment swings by 20% end to end, ahead of Repayment Period (about 13%, and in the opposite direction — a longer payoff window lowers the monthly bill) and HELOC Interest Rate (about 7%). Interest-Only Payment is a plain single-month interest charge on the full drawn balance (drawAmount × monthly rate, line 34) rather than an amortized figure, so unlike Monthly Payment it never responds to Repayment Period at all — it represents what you'd owe during the draw period, before repayment even starts. Current LTV edges toward Home Value slightly more than Current Mortgage Balance under an equal-percentage nudge, not because home value inherently matters more, but because Home Value sits in the denominator of the ratio, so a percentage change there scales the whole ratio inversely rather than adding linearly. This calculator does not account for a HELOC's typical variable rate resetting during repayment, annual fees, or a minimum draw requirement.