Estimate how much equity you can access from your home.
Max Combined Loan Amount:
Estimated HELOC Credit Limit:
Monthly Interest-Only Payment:
What is a HELOC?
A Home Equity Line of Credit (HELOC) is a revolving credit line that allows homeowners to borrow against the equity in their property. Unlike a standard home equity loan, which provides a lump sum, a HELOC works more like a credit card, where you can draw funds as needed up to a specific limit during a set "draw period."
How This HELOC Calculator Works
Lenders typically use a Combined Loan-to-Value (CLTV) ratio to determine how much you can borrow. Most lenders limit the CLTV to 80% or 85% of your home's current market value. The formula used in this calculator is:
(Home Value × Max CLTV %) – Existing Mortgage Balance = Your HELOC Limit
Realistic HELOC Example
Suppose your home is worth $450,000 and you still owe $250,000 on your primary mortgage. If a lender allows an 85% CLTV:
85% of $450,000 = $382,500 (Max combined debt allowed)
$382,500 – $250,000 = $132,500 (Your available HELOC limit)
Key Factors to Consider
Variable Rates: Most HELOCs have variable interest rates tied to the Prime Rate, meaning your payments can fluctuate over time.
Draw vs. Repayment Period: During the draw period (usually 10 years), you often only have to pay interest. After that, the repayment period begins, and you must pay back both principal and interest.
Appraisal Requirements: Your actual credit limit will depend on a professional appraisal to confirm your home's current market value.
function calculateHELOC() {
var homeValue = parseFloat(document.getElementById("homeValue").value);
var mortgageBalance = parseFloat(document.getElementById("mortgageBalance").value);
var cltvLimit = parseFloat(document.getElementById("cltvLimit").value);
var interestRate = parseFloat(document.getElementById("interestRate").value);
var resultBox = document.getElementById("helocResult");
if (isNaN(homeValue) || isNaN(mortgageBalance) || isNaN(cltvLimit) || homeValue <= 0) {
alert("Please enter valid numbers for home value, mortgage balance, and CLTV limit.");
return;
}
// Calculate max combined loan amount allowed
var maxCombinedDebt = homeValue * (cltvLimit / 100);
// Calculate HELOC limit by subtracting existing mortgage
var helocLimit = maxCombinedDebt – mortgageBalance;
// Safety check for negative equity availability
if (helocLimit < 0) {
helocLimit = 0;
}
// Calculate estimated monthly interest-only payment
var annualInterest = helocLimit * (interestRate / 100);
var monthlyInterest = annualInterest / 12;
// Formatting as currency
var formatter = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 0,
maximumFractionDigits: 0
});
var currencyFormatterDecimals = new Intl.NumberFormat('en-US', {
style: 'currency',
currency: 'USD',
minimumFractionDigits: 2,
maximumFractionDigits: 2
});
document.getElementById("maxLoanAmount").innerText = formatter.format(maxCombinedDebt);
document.getElementById("helocLimit").innerText = formatter.format(helocLimit);
document.getElementById("monthlyInterest").innerText = currencyFormatterDecimals.format(monthlyInterest);
resultBox.style.display = "block";
}