Calculate HELOC payments for both the interest-only draw period and principal + interest repayment period. See your full amortization schedule and payment shock analysis.
Draw period + repayment period breakdown
A home equity line of credit (HELOC) has two distinct phases that this calculator models separately. During the draw period — typically 5 or 10 years — you borrow up to your credit limit and make interest-only payments on the outstanding balance. If you draw the full $100,000 on a HELOC at 8.5%, your monthly interest payment during the draw period is $708. That feels manageable. Then the draw period ends and the repayment phase begins — usually 10 or 20 years of full principal plus interest payments on the balance. That $708 interest-only payment becomes $868 per month in P+I over 20 years, or $1,234 if you chose a 10-year repayment term. This "payment shock" surprises many borrowers who didn't plan for it.
HELOCs are variable-rate products tied to the Prime Rate, which is set by the Federal Reserve's federal funds rate decisions. In 2022–2023, the Prime Rate rose from 3.25% to 8.50% in 18 months — and HELOC rates followed automatically, with no opt-out. Homeowners who borrowed heavily on HELOCs during the low-rate era saw payments increase dramatically. Before opening a HELOC, model the payment at rates 2–3 percentage points higher than today's rate to stress-test your budget. The maximum HELOC credit line is typically limited to 85% of combined loan-to-value: on a $500,000 home with a $300,000 mortgage, the max HELOC is $125,000.
Average HELOC APR in May 2026: 8.0%–9.5% (prime rate sensitive). HELOCs are variable — tied to Prime Rate. A 1% Prime Rate increase automatically raises your HELOC rate by 1%, with no advance notice required.
When the draw period ends, your payment can jump 20%–75% overnight. A $100,000 HELOC at 8.5%: draw period = $708/mo (interest only) → repayment = $868/mo over 20 years or $1,234/mo over 10 years.
Lenders cap combined LTV at 85%. Formula: (Home Value × 0.85) minus Mortgage Balance = max HELOC. On a $500k home, $300k mortgage: max HELOC = $125,000. Some lenders go to 90%–95% at higher rates.
HELOCs have variable rates and flexible draws — ideal for phased home improvement projects. Cash-out refis offer fixed rates for the full term — better for large, one-time needs when today's rates are attractive.