HELOC Calculator
Enter your home value, your mortgage balance, the lender's max loan-to-value, the rate, the draw and repayment periods and the amount you want to borrow. The calculator shows your available equity, the most you can borrow under that limit, the interest-only payment in the draw period, the principal and interest payment in the repayment period, and the total interest over both. Fixed rate keeps one rate for both periods. Variable rate takes your own index or rate, your margin, your rate cap and the years the rate changes. It has no live index and guesses none, so those fields start empty. Both modes assume you draw the whole amount at the start.
Your rate
This page has no live index and does not guess one. Type your own figures. Use the index with a margin, or the full rate with no margin.
From your agreement. Empty counts as none.
From your agreement. Empty counts as none.
How to use the HELOC Calculator
- Enter your numbers in the HELOC Calculator above.
- Press the Calculate button to see the result.
- To try other numbers, change any value and press the button again.
The HELOC payment math
Max = Home value × LTV − Mortgage balance · · · Draw period: Payment = Balance × r · · · Repayment period: M = B · r(1 + r)^n / ((1 + r)^n − 1) · · · Variable rate: rate = index + margin, up to the cap
r is the annual rate divided by 12 and n is the repayment period in months. The draw payment covers interest only, so the balance stays the same until the repayment period starts. Total interest is the draw payment times the months of the draw period, plus all repayment payments, minus the amount borrowed. If you ask for more than the max, the calculator says so and uses the max. In the Variable rate mode a new rate starts at the beginning of a year you name. The draw payment follows the rate. In repayment the calculator works out a new level payment at each change, from the balance left and the months left.
Worked example
$50,000 drawn at 8.5%, with a 10-year draw period and a 20-year repayment period. The draw payment is $354.17 a month, interest only. The repayment payment is $433.91 a month, with a last payment of $434.74 that takes up the cent rounding, and total interest over the 30 years comes to $96,639.63. For the Variable rate mode, take made-up figures, which are no forecast: a 1% margin on an index of 7.5% from year 1, 8.5% from year 6, 6.5% from year 11 and 7% from year 16. The draw payment is $354.17, then $395.83 from year 6. Repayment starts at $402.80 and moves to $415.24 from year 16. Total interest is $93,910.67, which is $2,728.96 less than the $96,639.63 at 8.5% throughout.
Frequently asked questions
Why does my HELOC payment jump?
When the draw period ends, interest-only payments stop and you start paying down the balance as well. In the example above, $50,000 at 8.5% goes from $354.17 to $433.91 a month, $79.74 more. A shorter repayment period makes the jump larger.
Are HELOC rates fixed or variable?
Almost always variable, indexed to Prime Rate plus a margin (e.g., Prime + 1%). As the Fed moves rates, your HELOC rate moves with them. The Fixed rate mode keeps the rate you enter for both periods. The Variable rate mode takes your own path, so you can try a rise, a fall or the rates you have already paid.
Which index does the variable rate mode use?
The one you type. The calculator has no live index and assumes nothing about where one is going, so the rate fields start empty. Your agreement names the index, the margin and any cap. Enter the index with the margin, or enter your full rate and leave the margin empty.
How does the payment change when the rate changes?
In the draw period the payment is the balance times the new rate ÷ 12, so it moves at once. In repayment the calculator works out a new level payment from the balance left and the months left. In the example, the move to 8% in year 16 takes the payment from $402.80 to $415.24 with 180 months left. It changes rates only at the start of a year, and your agreement decides how often yours moves.
Can I freeze my HELOC?
Banks can freeze or reduce HELOC limits if home value drops or your financial situation changes. This happened widely in 2008–2009 — don't rely on a HELOC as guaranteed emergency funds.