A familiar situation
A HELOC’s interest-only draw-period cost changes with both balance and rate. Enter the current figures to estimate one month’s interest, remembering that variable rates and repayment terms can change.
How to use this calculator
- Enter current balance, annual interest / apr, monthly payment.
- Select Calculate to see the answer and its breakdown.
- Keep a scenario, change an input and compare the results.
Use consistent units and check the assumptions below before applying the result.
How heloc is calculated
The balance is charged interest each month before the fixed payment is applied. The estimate assumes no new purchases, rate changes or penalties during payoff. Formula: Interest-only amount = balance × annual rate ÷ 12. Use the displayed details to inspect the intermediate amounts and replace example assumptions with terms from your own quote or records.
Interest-only amount = balance × annual rate ÷ 12.A $40,000 balance at 8% costs about $267 monthly in interest only.
Assumptions & useful context
Interest-only estimate; the balance does not decline and the rate may vary.
Financial projections use your assumptions. Actual returns, lender terms, fees and tax rules can differ; these results do not guarantee a future outcome.
Frequently asked questions
HELOC Calculator: what does the result include?
A payment must exceed the first month’s interest for the balance to decline. The calculator reports an error when the entered amount cannot amortize the debt.
HELOC Calculator: which assumptions matter most?
No. The calculation assumes the balance receives no new charges and that the APR remains constant.