Enter your balance, rate, and repayment term, then calculate to see the estimated jump from interest-only to repayment.
About the HELOC payment shock calculator
The HELOC payment shock calculator estimates how much your monthly payment can rise when a home equity line of credit moves from its interest-only draw period into the principal-and-interest repayment period. Enter your outstanding balance, the annual interest rate, and the repayment term, and it compares the two payments so you can plan ahead.
During the draw period many HELOCs let you pay interest only, which keeps the monthly payment low. When repayment begins, you start paying down principal and interest together over a fixed term, and the payment can jump sharply. This is a planning estimate, not financial advice or an offer of credit. Actual terms, rates, and the timing of the draw-to-repayment transition depend on your lender and your agreement, so confirm the numbers with your lender before relying on them.
How to use
- Enter your outstanding HELOC balance in dollars.
- Enter the annual interest rate as a percentage.
- Enter the repayment term in whole years.
- Select Calculate payment shock to see the interest-only payment, the repayment payment, and the estimated monthly and annual increase.
- Confirm the figures with your lender, since rates and terms vary and can change.
Worked examples
A $50,000 balance at 8.5% can jump about $80 per month
An interest-only draw payment near $354 can rise to about $434 once a 20-year repayment period begins on the same balance.
A shorter repayment term means a larger monthly increase
The same balance repaid over 10 years has a higher principal-and-interest payment than one repaid over 20 years, so the payment shock is larger.
A higher rate raises both payments and the gap between them
Because the draw payment is interest only, a higher rate increases the interest-only payment and the repayment payment, and usually widens the increase.
Frequently asked questions
- What is HELOC payment shock?
- Payment shock is the increase in your monthly payment when a HELOC moves from the interest-only draw period to the principal-and-interest repayment period. During repayment you pay down the balance as well as the interest, so the payment is usually higher.
- How is the increase calculated?
- The tool estimates the interest-only payment as the balance times the monthly rate, and the repayment payment as a fully amortizing principal-and-interest payment on the same balance over the repayment term you enter. The increase is the difference between the two.
- Is this financial advice?
- No. This is a free planning estimate. It does not quote a loan, create an offer of credit, or replace guidance from your lender. Your actual HELOC terms, rate, and repayment schedule may differ.
- Does the calculator account for a variable rate?
- It uses the single rate you enter for both the interest-only and repayment estimates. Many HELOCs have variable rates, so a real payment can be higher or lower if the rate changes. Run the tool again with a different rate to see the effect.
- Do you store the numbers I enter?
- No. The calculation runs entirely in your browser, and the balance, rate, and term you enter are not saved or sent to a server.
- Does it work on mobile?
- Yes. The calculator is built to work on phones and desktops.
- Is the HELOC payment shock calculator free?
- Yes. It is free to use and does not require an account.
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