HELOC Calculator

Credit limit, interest-only draw period payment and repayment period payment for a home equity line of credit. Results update as you type.

Home value

Current mortgage balance

Maximum LTV (%)

Draw amount

Interest rate (annual %)

Draw period (years)

Repayment period (years)

Draw period payment (interest only)

$0.00

Cost breakdown

Yearly payment

How this calculator works

A HELOC limit is set by the home value times the maximum loan-to-value ratio, minus the current mortgage balance. During the draw period you pay interest only on the amount drawn. During repayment, the drawn amount is paid off like a regular loan.

Results are estimates for education only and are not financial advice.

What happens when the draw period ends?

When the draw period ends you can no longer borrow, and the balance enters the repayment period, where each payment covers interest plus principal until the balance is paid off. The repayment payment here assumes the full draw amount is repaid over the repayment period at the same rate.

HELOC limit and payment formulas

Maximum credit = home value × maximum LTV. Credit limit = maximum credit − current mortgage balance, never below zero. Draw period payment = draw amount × annual rate ÷ 100 ÷ 12 (interest only). Repayment payment = P × r ÷ (1 − (1 + r)^(−n)) on the draw amount over the repayment period.

How the calculation works, step by step

Multiply the home value by the maximum LTV percentage to get the maximum credit the home can support.
Subtract the current mortgage balance from the maximum credit to get the available credit limit, floored at zero.
During the draw period, the monthly payment is interest only: the draw amount times the annual rate divided by 12.
During the repayment period, the draw amount is paid off like a regular loan using the amortization formula over the repayment years.

Worked example

A $600,000 home with a $300,000 mortgage balance and an 80% maximum LTV gives maximum credit of $480,000 and a credit limit of $180,000. Drawing $100,000 at 9% costs $750.00 per month during the draw period, and $899.73 per month over a 20-year repayment period.

Is HELOC interest tax deductible?

In general, HELOC interest is deductible only when the borrowed money is used to buy, build, or substantially improve the home that secures the loan. Interest on money used for other purposes, such as paying off credit cards, is generally not deductible. Tax rules change, so the current IRS rules apply.

Can my lender reduce or freeze my credit line?

Yes. If the home's value drops significantly, the lender may reduce the credit limit or freeze the line, and a borrower's financial situation can also trigger a freeze. The line is secured by the home, so the lender protects its position when the collateral value falls.