HELOC Payment Calculator
See your interest-only payment during the draw period and what your payment jumps to once the repayment period kicks in.
*Estimates only. HELOC rates are usually variable and can change. Not financial advice.
Comparing against a traditional mortgage refinance?
Mortgage Loan Calculator🏠 Understanding Your HELOC Payment
A HELOC works nothing like a fixed-rate loan — the payment structure changes fundamentally halfway through.
How it Works
During the draw period you borrow against your home's equity like a credit card and typically only owe interest each month. Once the draw period ends, the outstanding balance converts into a fully amortizing loan.
The Formula
Draw payment = Balance × (APR/12). Repayment payment = Balance × r / (1 − (1+r)⁻ⁿ), where r is the monthly rate and n is the number of repayment months.
Pro Tip
Making extra principal payments during the draw period — even though they aren't required — can meaningfully lower the payment shock when repayment begins.
Frequently Asked Questions
What is a HELOC and how does the payment change over time? +
A home equity line of credit (HELOC) has two phases: a draw period (often 10 years) where you typically only pay interest on what you've borrowed, and a repayment period (often 15-20 years) where the balance amortizes into fixed principal-plus-interest payments. Your payment can jump significantly once the draw period ends.
Why is my interest-only payment so much lower than the repayment period payment? +
During the draw period you're only covering the interest charge on the outstanding balance, so none of your payment reduces principal. Once repayment begins, the lender amortizes the remaining balance over the repayment term, so each payment includes both interest and principal, which raises the monthly amount considerably.
Is HELOC interest a variable rate? +
Most HELOCs carry a variable interest rate tied to the prime rate plus a margin. This calculator assumes a fixed APR for simplicity, but in practice your real payment will fluctuate as the index rate changes, especially during a multi-year draw period.
Can I pay down principal during the draw period? +
Yes. Most HELOCs allow optional principal payments during the draw period even though only interest is required. Paying extra principal early reduces the balance that carries into the repayment period, lowering your future required payment.
What happens if I keep withdrawing money during the draw period? +
This calculator assumes a fixed starting balance with no further draws. If you continue borrowing against the line, your balance and interest-only payment will rise, and the amount amortized in the repayment period will also be larger than shown here.