HELOC payment calculator.

How the numbers work

During the draw period most HELOCs require only interest on what you have borrowed: payment = balance × annual rate ÷ 12. When the repayment period starts, the balance is amortized over the repayment term with the standard formula P = B × r / (1 − (1 + r)⁻ⁿ), where r is the monthly rate and n the number of repayment months. The difference between the two is the payment jump. The same two payments are shown at the lifetime cap rate you enter, since most variable-rate plans cap the rate. CLTV (combined loan-to-value) = (first mortgage balance + the full HELOC limit) ÷ home value; lenders typically count the whole limit, not just what you have drawn.

Worked example

$60,000 drawn at 8.5%: interest-only is $60,000 × 0.085 ÷ 12 = $425.00 a month. Repaid over 20 years at the same rate the payment is about $520.69, a jump of roughly $96. At an 18% cap the interest-only payment is $900.00 and the 20-year repayment payment is about $925.99. With a $100,000 limit, a $250,000 first mortgage and a $500,000 home, CLTV = ($250,000 + $100,000) ÷ $500,000 = 70.0%.

Source and as-of date

Under Regulation Z, 12 CFR 1026.40, a HELOC creditor must disclose the length of the draw and any repayment period, a minimum-payment example based on a $10,000 balance, and for variable-rate plans the maximum APR and the minimum payment at that maximum rate. Source: 12 CFR 1026.40 (Cornell LII), read September 30, 2026. The payment math here is standard amortization; no rates, caps or limits are assumed beyond what you enter, and your plan's own disclosure is what governs.

FAQ

Why does my payment jump when the draw period ends?

Interest-only payments never reduce principal. Once repayment begins you pay interest plus principal over a fixed term, so the same balance costs more each month.

Is my rate really fixed at today's rate?

Usually not. Most HELOCs are variable, so this tool shows today's rate and your cap as two scenarios rather than predicting the rate. Your cap is in your plan disclosure.

What if I keep drawing or paying down during the draw period?

This tool uses the balance you enter as the balance when repayment starts. Change the drawn balance to model a different amount.

Comparing against a fixed home equity loan?

Use the home equity loan vs HELOC calculator. Canadian borrowers can use the Canada HELOC calculator.

This tool is a planning estimate, not financial advice. It assumes monthly payments and ignores taxes, annual fees, rate changes and plan-specific minimum-payment rules.