Estimate your available credit line and potential monthly payments.
Total Max Loan-to-Value (LTV):
Available HELOC Credit Limit:
Remaining Equity After Limit:
Est. Interest-Only Monthly Payment:
How to Calculate Your HELOC Limit
A Home Equity Line of Credit (HELOC) allows you to borrow against the value of your home. Most lenders will allow you to borrow up to a specific Combined Loan-to-Value (CLTV) ratio, typically between 80% and 85% of your home's appraised value.
The formula used in this calculator is:
(Home Value × LTV Limit %) – Current Mortgage Balance = Available HELOC
Practical Example
If your home is worth $500,000 and your lender allows an 80% CLTV:
Total allowable debt: $500,000 × 0.80 = $400,000
If you owe $300,000 on your primary mortgage…
Your maximum HELOC limit: $400,000 – $300,000 = $100,000
Understanding Interest-Only Payments
During the "draw period" (usually the first 10 years), many HELOCs only require interest-only payments. Our calculator estimates this payment based on your planned draw amount and current interest rates. Note that HELOC rates are usually variable and tied to the U.S. Prime Rate, meaning your payment can change over time.
Important Considerations
Appraisal: Lenders will require a professional appraisal to confirm your home's value.
Credit Score: Higher credit scores often unlock higher LTV limits and lower interest rates.
Closing Costs: While often lower than a standard mortgage, HELOCs may have application fees, appraisal fees, or annual maintenance fees.
Risk: Your home serves as collateral. Failure to make payments could lead to foreclosure.
function calculateHELOC() {
var homeValue = parseFloat(document.getElementById('homeValue').value);
var mortgageBalance = parseFloat(document.getElementById('mortgageBalance').value);
var ltvLimit = parseFloat(document.getElementById('ltvLimit').value);
var interestRate = parseFloat(document.getElementById('interestRate').value);
var drawAmount = parseFloat(document.getElementById('drawAmount').value);
if (isNaN(homeValue) || isNaN(mortgageBalance) || isNaN(ltvLimit) || isNaN(interestRate)) {
alert("Please enter valid numbers in all required fields.");
return;
}
// Calculate Max LTV Dollar Amount
var maxLtvAmount = homeValue * (ltvLimit / 100);
// Calculate Available Credit Limit
var availableLimit = maxLtvAmount – mortgageBalance;
if (availableLimit < 0) availableLimit = 0;
// Calculate Remaining Equity
var remainingEquity = homeValue – mortgageBalance – availableLimit;
// Calculate Interest-Only Payment
// Formula: (Draw Amount * Annual Rate) / 12 months
var monthlyPayment = (drawAmount * (interestRate / 100)) / 12;
// Formatting
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
});
document.getElementById('resMaxLtv').innerText = formatter.format(maxLtvAmount);
document.getElementById('resCreditLimit').innerText = formatter.format(availableLimit);
document.getElementById('resRemainingEquity').innerText = formatter.format(remainingEquity);
document.getElementById('resMonthlyPayment').innerText = formatter.format(monthlyPayment);
// Show results
document.getElementById('helocResults').style.display = 'block';
}