HELOC Calculator
Estimate how much you can borrow with a HELOC against your home's equity, plus your payment during the interest-only draw period and the full payment during the repayment period.
Available Equity
$370,000
Home value − current mortgage
Effective CLTV
54.62%
After drawing
Total Interest
$144,958
Over 30 total years
Interest-only payments on the drawn balance of $75,000. You can borrow, repay, and re-borrow up to your credit limit. Total interest this phase: $63,750.
Principal + interest — the HELOC is closed to new draws and the outstanding balance amortizes over 20 years. Total interest this phase: $81,208.
HELOC rates are almost always variable — they adjust with the prime rate, so your actual payment can change month-to-month. This calculator assumes a fixed rate for simplicity. When comparing to a home equity loan (which IS fixed-rate and lump-sum), factor in the rate risk.
How to use this calculator
Enter your home's current value (what it would sell for today) and your current mortgage balance. The difference is your total equity — but lenders only let you tap part of that.
The CLTV limit slider controls how much of your home value the lender will lend against, combined across all mortgages. Most lenders cap CLTV at 80-85%; some premium programs go to 90%+. The calculator uses your CLTV setting minus your current mortgage balance to compute the maximum HELOC you can get.
Set your desired draw amount — this is how much you actually want to borrow right now. It can be anywhere from $0 up to the maximum.
The draw period (typically 10 years) is when you can borrow, repay, and re-borrow — with interest-only payments. The repayment period (typically 10-20 years) kicks in after that: the line closes and you pay principal + interest.
How it works
A Home Equity Line of Credit (HELOC) is a revolving credit line secured by the equity in your home. It works like a credit card with a much lower interest rate: you have a credit limit, you draw what you need, you pay interest only on what you've drawn, and you can pay it back and re-borrow during the draw period.
A HELOC has two distinct phases.
Phase 1 — Draw Period (typically 10 years): You can borrow up to your credit limit, repay, and borrow again. Your monthly payment is interest-only on whatever balance you're carrying. This makes the payment very low relative to the balance. Some lenders let you pay extra principal during the draw period; some don't.
Phase 2 — Repayment Period (typically 10-20 years): The line closes — you can no longer borrow. The outstanding balance amortizes over the repayment period like a regular loan: principal + interest each month. The payment often jumps significantly when this transition happens.
HELOC rates are almost always variable. They're pegged to the prime rate (plus a margin), so your payment can change as the Fed raises or lowers rates. This is the main risk of a HELOC — a payment that's affordable today could become painful if rates climb. The home equity loan is the fixed-rate alternative: a lump-sum loan with a fixed rate and fixed monthly payment.