How much can you borrow with a HELOC?

How much a home equity line of credit (HELOC) can be comes down to one subtraction, one percentage that differs from lender to lender, and a lender's view of you as a borrower. The arithmetic is simple. The percentage is the part people get wrong.

Combined loan-to-value: the number the lender caps

A lender does not lend against your equity directly. It caps the total of everything secured on the home, as a percentage of the home's value. That total over the value is the combined loan-to-value, or CLTV. The CFPB's HELOC booklet describes how much you can borrow as "Generally a percentage of the appraised value of your home, minus the amount you owe on your mortgage".

So the line is:

Take a $400,000 home with $250,000 left on the mortgage. At an 85% cap, the lender's limit is $340,000; subtract the $250,000 and the line is $90,000. At 80% it would be $70,000, and at 90%, $110,000. Your CLTV today is 62.5%.

"Everything you owe" means every lien, not only the first mortgage: a second mortgage, a home equity loan, or another line all count against the same cap. And when what you owe is already at or above the cap, the line is zero, not negative. Paying the balance down, or the home's value rising, is what opens one.

The HELOC limit calculator does this at several caps at once, including your lender's if you know it.

Why the cap varies by lender

No regulation sets a HELOC's CLTV cap. Each lender chooses its own, as a matter of its credit policy and appetite for risk, and the same borrower can be offered different caps by different lenders, or by the same lender at different times. That is why this guide and the calculator show 80%, 85% and 90% as points to compare rather than naming a "typical" figure: there is no published rule to call typical. Ask each lender for its maximum CLTV, and whether it changes with your credit score or the loan amount.

The value is the lender's, not yours

The cap applies to the value the lender accepts, which comes from an appraisal or a cheaper automated estimate. The federal banking agencies' guidance on home equity lending warns that "Use of several valuation tools may return different values for the same property", and tells lenders that "If several different valuation tools or AVMs are used for the same property, the institution should adhere to a policy for selecting the most reliable method, rather than the highest value."

Every $1,000 the valuation comes in below your estimate takes $850 off an 85% line. If your estimate is generous, the line will be smaller than the calculator suggests.

Credit and income set how much of it you get

Equity sets the ceiling. Whether you are approved for all of it is an underwriting decision. The same guidance says underwriting factors "should include a borrower's income and debt levels, credit score (if obtained), and credit history, as well as the loan size, collateral value (including valuation methodology), lien position, and property type and location", and that "an evaluation of repayment capacity should consider a borrower's income and debt levels and not just a credit score."

It also says that for interest-only and variable-rate lines, underwriting "should include an assessment of the borrower's ability to amortize the fully drawn line over the loan term and to absorb potential increases in interest rates." That is a useful test to run on yourself. On the $90,000 line above at 9%, interest only during the draw period is $675 a month. Repaid over 15 years, the payment is about $913, and more if the rate rises. If the second figure does not fit your budget, the full line is more than you should plan to use. The CFPB booklet notes the repayment schedule is "often over ten or 15 years"; your agreement gives the real term.

Lines can be frozen or reduced

A HELOC's limit is not fixed for life. The CFPB booklet says "HELOCs generally permit the lender to freeze or reduce your credit line if the value of your home falls or if they see a change for the worse in your financial situation."

Regulation Z sets out when a lender may "prohibit additional extensions of credit or reduce the credit limit". Among the circumstances it lists: "The value of the dwelling that secures the plan declines significantly below the dwelling's appraised value for purposes of the plan", and "The creditor reasonably believes that the consumer will be unable to fulfill the repayment obligations under the plan because of a material change in the consumer's financial circumstances". In practice, the money you have not drawn yet is the money most at risk when house prices fall, so do not plan around it.

What to do next

The line tells you what is possible, not whether to take it. To compare a HELOC with replacing your mortgage, use the HELOC or cash-out refinance calculator: it turns on what happens to the rate you already have. If the plan is to clear credit cards, the HELOC payoff calculator shows what the draw period and the payment step do to that plan.

Sources: Consumer Financial Protection Bureau, What you should know about Home Equity Lines of Credit (2022). Board of Governors of the Federal Reserve System and the other federal banking agencies, Credit Risk Management Guidance for Home Equity Lending (SR 05-11, 2005, revised June 2026). 12 CFR 1026.40(f)(3)(vi) (Regulation Z). Payment figures computed with this site's own amortization.