HELOC Calculator

Almost always variable. The rate is built from an index, nearly always the prime rate, plus a fixed margin the lender assigns when you open the line. If prime is 8.50% and your margin is zero, you pay 8.50%. When the Federal Reserve moves and prime follows, your rate resets at the next adjustment. The margin itself never changes for the life of the line, which is why it is worth negotiating up front. Many lenders also offer a fixed-rate lock feature that converts part or all of the drawn balance to a set rate for a set term, useful once you have pulled a large amount and want that portion to stop moving.

Bigger than most borrowers expect, because interest-only payments never touch principal. On $80,000 at 8.5%, the draw-period payment is about $567 a month. Once repayment starts, the same balance amortized over 20 years costs roughly $694 a month, over 15 years about $788, and over 10 years about $992, which is 75% above the payment you were used to. The repayment term is written into your agreement rather than chosen at the reset, so find that clause now. Paying down principal voluntarily during the draw years shrinks the balance that converts and softens the whole thing.

Lenders measure combined loan-to-value: your first mortgage balance plus the HELOC limit, divided by the home's value. Most cap CLTV between 80 and 90%. On a $500,000 home with a $300,000 mortgage, an 85% cap allows $425,000 of total secured debt, which leaves room for a line up to $125,000. Credit matters alongside equity. Most lenders want a score of at least 680 and set your margin by tier, so a 740-plus borrower might pay prime with no margin while a 680 borrower pays prime plus 1.5 to 2%. On an $80,000 balance that spread is worth $100 to $133 a month.

Sometimes. Since the Tax Cuts and Jobs Act took effect in 2018, HELOC interest is deductible only when the money buys, builds, or substantially improves the home that secures the line. A kitchen remodel qualifies. Consolidating card debt or buying a car does not, even though the loan is secured by the house. The deduction also sits inside the overall cap on home loan interest, which applies to $750,000 of combined mortgage debt for most filers. Keep records showing where each draw went, and confirm the current rules at irs.gov or with a tax preparer, since this treatment has changed before and is scheduled to be revisited.

Yes. Federal rules let a lender freeze or cut a HELOC under defined conditions: a significant decline in the home's value, a material change in your finances, or default on the agreement. Value declines are the usual trigger, and lenders froze lines across entire regions in 2008 and 2009 when prices fell. A freeze blocks new draws but does not call the loan; you keep repaying the existing balance on the existing terms. The lender must notify you in writing with the specific reason, and you can request reinstatement once values recover or your finances improve. The CFPB explains these protections and what to do if you think a freeze was applied unfairly.