🏦 HELOC Payment Calculator
Calculate your Home Equity Line of Credit (HELOC) monthly payments for both the draw period (interest-only) and repayment period (principal + interest). Includes full amortization schedule and payment shock analysis.
What Is a HELOC Payment Calculator?
A HELOC payment calculator helps you estimate your monthly payments for a Home Equity Line of Credit (HELOC). HELOCs have two distinct phases:
- Draw Period , typically 10 years where you can borrow funds and usually only pay interest on the outstanding balance.
- Repayment Period , typically 20 years where you can no longer borrow and must repay both principal and interest through an amortizing loan.
Many borrowers are surprised when their payment increases significantly at the start of the repayment period , sometimes doubling or tripling. This calculator helps you see that coming.
How Does the HELOC Payment Calculator Work?
The calculator uses standard financial formulas for both phases:
Interest-Only (Draw Period): Monthly Payment = Balance × (Annual Rate ÷ 12)
Principal + Interest (Repayment Period): Payment = P × [r(1+r)^n] ÷ [(1+r)^n − 1]
Where P = principal balance at start of repayment, r = monthly interest rate, and n = number of monthly payments.
Why Use This HELOC Payment Calculator?
- Two-Phase Analysis: See both interest-only and fully-amortizing payments.
- Payment Shock Warning: Understand the potential payment increase when your draw period ends , often 2–3× higher.
- Full Amortization Schedule: See every payment over the life of the HELOC.
- Visual Chart: Compare draw and repayment payments at a glance.
- Free & Private: No registration, no data storage , all calculations are done in your browser.
❓ HELOC Payment Calculator FAQ
What is a HELOC draw period?
The draw period is the initial phase of a HELOC, typically lasting 10 years. During this time, you can borrow funds up to your credit limit and usually only need to make interest-only payments on the outstanding balance.
What is a HELOC repayment period?
The repayment period begins after the draw period ends, typically lasting 10-20 years. You can no longer borrow funds, and your payments include both principal and interest to fully amortize the remaining balance.
What is "payment shock"?
Payment shock is the sudden increase in your monthly payment when your HELOC transitions from the interest-only draw period to the fully-amortizing repayment period. This increase can be 2-3 times your draw period payment.
How is the interest-only payment calculated?
The interest-only payment is calculated using the formula: Balance × (Annual Rate ÷ 12). For example, a $50,000 balance at 8.5% APR gives: $50,000 × (0.085 ÷ 12) = $354/month.
How is the repayment period payment calculated?
The repayment period payment uses the standard amortization formula: P × [r(1+r)^n] ÷ [(1+r)^n − 1]. For a $50,000 balance at 8.5% over 20 years: approximately $434/month.
What happens if I make extra payments during the draw period?
Extra payments during the draw period reduce your outstanding balance, which lowers your interest-only payment immediately since the payment is based on the current balance.
Is the HELOC interest rate fixed or variable?
Most HELOCs have variable interest rates tied to the Prime Rate plus a margin. Your rate can change monthly or quarterly, which affects both your draw and repayment payments.
How accurate is this calculator?
This calculator provides accurate estimates based on standard HELOC formulas. However, actual payments depend on your specific HELOC terms, rate adjustments, and lender policies. Use this as a planning tool and consult your lender for precise numbers.
Is this calculator free to use?
Yes, this calculator is completely free to use. No registration or personal data storage is required. All calculations are performed in your browser.
What is the typical HELOC term?
The most common HELOC structure is 10 years draw + 20 years repayment for a total of 30 years. Some lenders offer 5+15, 10+15, or 10+10 structures.