Maximum HELOC line from your lender's CLTV limit, plus CLTV and HCLTV
Updated 2026-10-02
The most you can borrow with a home equity line of credit (HELOC) is your home's value times the lender's maximum combined loan-to-value (CLTV), minus what you already owe. Enter the value, your mortgage balance and the lender's limit: the calculator gives the maximum line, your CLTV and HCLTV, and the interest-only payment on what you draw. Compare a new mortgage payment ยท compare a cash-out refinance.
Your home and loans
What you can borrow
Maximum HELOC line
$125,000
at 85% CLTV on $500,000
CLTV (drawn balance)
70%
now 60% before the HELOC
HCLTV (full line)
85%
equity $200,000
Interest-only draw payment
$354.17
on $50,000 drawn
Estimates for planning, not a loan offer or financial advice. Every rate and cost here is a number you enter or an example you can change; confirm figures with your lender.
How the HELOC limit is calculated
Maximum line = home value ร maximum CLTV โ all existing mortgage balances CLTV = (mortgages + drawn HELOC) รท value ยท HCLTV = (mortgages + full HELOC line) รท value
The definitions come from Fannie Mae's Selling Guide (current guide published September 2026). B2-1.2-02, Combined Loan-to-Value (CLTV) Ratios divides the loans secured by the home, counting only the drawn portion of a HELOC, by the lower of the sales price or the appraised value. B2-1.2-03, Home Equity Combined Loan-to-Value (HCLTV) Ratios uses the full HELOC credit line, drawn or not, and the CLTV can never exceed the HCLTV. These rules govern first mortgages Fannie Mae buys; the HELOC lender sets its own maximum, which you enter above.
Worked example
Your home is worth $500,000 and you owe $300,000, an LTV of 60%. A lender that allows 85% CLTV will lend up to $425,000 in total, so the largest line is $125,000. If you open the full line and draw $50,000, the CLTV is 70% and the HCLTV is 85%. At 8.5%, interest on the $50,000 drawn is about $354.17 a month during the draw period.
Before you open a HELOC
Your home is the collateral. The CFPB's HELOC brochure explains that missing payments can put the home at risk, and that the lender can freeze or reduce the line in some circumstances, such as a significant drop in the home's value.
Variable rate. Most HELOC rates follow an index, so the payment changes with rates. Ask about rate caps and conversion options.
Two phases. During the draw period the minimum may be interest only; afterwards you repay principal too, and the payment rises. The interest-only calculator shows how large that jump can be.
Fees and minimum draws. Compare closing costs, annual fees and any early-closure fee across offers.
A cash-out refinance replaces the first mortgage instead; with a low existing rate, a HELOC often costs less overall, but compare both. This is an estimate for planning, not a loan offer.
Planning a home project?
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Multiply your home's value by the lender's maximum combined loan-to-value (CLTV) and subtract what you owe on every existing mortgage. With a $500,000 home, an 85% limit and a $300,000 first mortgage: $425,000 โ $300,000 = a $125,000 line.
What is CLTV?
Combined loan-to-value is the total of all loans secured by the home divided by its value. Fannie Mae's Selling Guide (B2-1.2-02) counts the first mortgage, the drawn balance of any HELOC and the balance of any other subordinate loan, divided by the lower of the sales price or appraised value.
What is the difference between CLTV and HCLTV?
CLTV counts only the part of a HELOC you have drawn. HCLTV (home equity combined loan-to-value, Fannie Mae B2-1.2-03) counts the full credit line whether or not you have used it. A HELOC lender sizing a new line looks at the full line, which is why the calculator shows both.
What is the maximum CLTV for a HELOC?
There is no single federal limit for a stand-alone HELOC. Each lender sets its own maximum, often depending on credit score, occupancy and line size. Enter the limit from your lender's offer; 85% is used here only as an example.
How is the HELOC payment calculated during the draw period?
Many HELOCs require only interest during the draw period: the drawn balance times the rate divided by 12. $50,000 drawn at 8.5% is about $354.17 a month. HELOC rates are usually variable, so the payment changes when the index moves, and principal payments start when the draw period ends.
