This HELOC calculator estimates your home equity line of credit payments: the interest-only payment during the draw period, the larger payment once repayment begins, total interest, and what happens if the variable rate rises.
How HELOC payments work
A HELOC has two phases. During the draw period, often 10 years, you can borrow as needed and many lenders require only interest payments. During the repayment period, often 20 years, you can no longer borrow and you repay principal plus interest.
Interest-only payment = balance × rate ÷ 12
Repayment payment = standard loan payment on the balance over the repayment period
Worked example
Borrowing $50,000 at 8.5% costs about $354.17 a month in interest during a 10-year draw period. When the 20-year repayment period starts, the payment rises to about $433.91 a month. If the rate rose by 2 points, that repayment payment would be about $499.19.
HELOC vs home equity loan
| HELOC | Home equity loan | |
|---|---|---|
| Money received | Draw as needed | One lump sum |
| Rate | Usually variable | Usually fixed |
| Payments | Change with balance and rate | Fixed |
| Interest charged on | Only what you draw | The full loan |
Avoiding payment shock
- Pay down principal during the draw period, even if only interest is required.
- Ask whether part of the balance can be converted to a fixed rate.
- Plan for the repayment payment before you borrow, not when it arrives.
Frequently asked questions
What is a HELOC draw period?
It is the first phase of the line, often 5 to 10 years, when you can borrow and repay as needed. Many HELOCs require only interest payments during this time.
Why does my HELOC payment go up?
When the draw period ends, you start repaying principal as well as interest, and the variable rate may also have risen.
Are HELOC rates fixed or variable?
Most are variable and tied to the prime rate plus a margin. Some lenders let you lock part of the balance at a fixed rate.
How much can I borrow with a HELOC?
Typically up to 80% to 85% of your home’s value minus your mortgage balance. Use the home equity calculator to estimate it.
Is HELOC interest tax-deductible?
In the US, generally only when the money is used to buy, build or substantially improve the home that secures the loan, and you itemize deductions.
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Last reviewed: October 2026. This calculator is for education only and is not financial, tax or legal advice.