HELOC calculator
Enter your home equity and draw, see the payments.
How is a HELOC payment calculated?
During the draw period many HELOCs require interest only: balance × rate ÷ 12. $50,000 at 8% is $333.33 a month. In the repayment period the balance is paid off with principal and interest — $418.22 a month over 20 years.
How much can I borrow with a HELOC?
Lenders cap the combined loan-to-value (all loans ÷ home value). At an 80% limit on a $400,000 home with $250,000 owed: $320,000 − $250,000 = $70,000. Enter your lender’s limit.
Why does the payment jump later?
When the draw period ends, you start repaying principal too, over a shorter time — in the example the payment rises by $84.89.
Is the HELOC rate fixed?
Usually not: most HELOCs have a variable rate, so payments change when rates do. The calculator uses today’s rate throughout.
What does the total interest include?
Interest-only payments for the whole draw period on the full balance, plus the interest in the repayment period — $90,372.81 in the example.
Do I pay interest on the whole credit line?
No. Interest is charged on the balance you have drawn, not on the limit. Drawing $20,000 of a $70,000 line at 8% costs $133.33 a month interest-only, against $333.33 for $50,000. The calculator uses the balance you enter; to see a drawn amount, enter it, not the line.
What happens to the payment if the rate rises?
For a variable-rate HELOC the interest-only payment moves with the rate. On a $50,000 balance, 8% costs $333.33 a month and 10% costs $416.67, a rise of $83.33. In the repayment period the payment at 10% over 20 years is $482.51, and total interest grows from $90,373 to $115,803.
How the two phases work
A HELOC is a revolving line secured by your home. During the draw period, which the CFPB says could last 10 years, for example, you can borrow up to the limit, and many HELOCs set a minimum monthly payment based on the balance. The calculator shows the interest-only case: balance × annual rate ÷ 12. When the draw period ends, borrowing stops and the repayment period begins. The balance is then paid off with level payments over the repayment term, using the standard loan formula, payment = balance × r ÷ (1 − (1 + r)^−n), with r the monthly rate and n the number of months.
The available credit line is the home value times the lender's combined loan-to-value limit, minus what you owe on the mortgage: 400,000 × 80% − 250,000 = $70,000 for the example in the FAQ. Lenders set their own limits, and other factors such as credit and income also matter.
Worked example
Take $50,000 at 8% with a 10-year draw period and 20-year repayment. The interest-only payment is $333.33 a month, and $40,000 in interest is paid over the draw period without reducing the balance. Repayment is $418.22 a month for 240 months, which adds $50,373 of interest; the total interest is $90,373. The jump at the start of repayment is $84.89 a month.
Things to watch
Payment shock is the first: the interest-only payment does not reduce the balance, so the payment steps up when repayment begins, and with a variable rate it can rise again. The second is that the lender can restrict borrowing. The CFPB notes that a significant drop in the value of the home, or a change in your finances that raises doubts about your ability to pay, can lead the lender to stop further credit. The third is that the home is the collateral: if you fall behind or cannot repay on schedule, you could lose it. Ask the lender for the draw and repayment terms, the margin over the index, any fees and the rate cap before you rely on a payment estimate.
Sources: Consumer Financial Protection Bureau, “What is a HELOC?” (draw period, repayment period, lender limits on access, risk to the home); the payment formulas are the standard level-payment loan formulas. Related tools: loan-to-value, interest-only mortgage, amortization and mortgage calculators.
Estimates for planning only — not financial advice. Your lender's figures decide. How we check our calculators.