HELOC Payments: How Much Will You Pay Each Month?

This HELOC payment calculator estimates a fixed monthly payment for a home equity line of credit, using the amount borrowed, APR, and repayment term you enter. It returns the estimated payment and total interest; actual HELOC bills can vary because many lines have variable rates and separate draw and repayment periods.

Formula

The calculator treats the balance as a fully amortizing loan with equal monthly payments and a fixed APR for the entire repayment term. It uses:

• Monthly payment: M = round(P × r ÷ [1 − (1 + r)⁻ⁿ], 2)
• Total interest: I = (M × n) − P

P is the amount owed in dollars, APR is the annual percentage rate entered as a percent, r is the monthly rate (APR ÷ 1,200), n is the number of monthly payments (years × 12), M is the payment in dollars rounded to cents, and I is estimated interest in dollars. The calculator uses the rounded monthly payment when estimating total interest, so totals reflect that payment amount.

Worked Example

Using the calculator’s defaults—$20,000 balance, 8% APR, and a five-year repayment term:

1. Convert the APR to a monthly rate: r = 8 ÷ 1,200 = 0.0066667.
2. Convert the term to payments: n = 5 × 12 = 60.
3. Apply the payment formula: M = $20,000 × 0.0066667 ÷ [1 − (1.0066667)⁻⁶⁰] = $405.53 per month, rounded to cents.
4. Estimate total interest using the rounded payment: I = ($405.53 × 60) − $20,000 = $4,331.80.

Assumptions

• The APR stays fixed throughout the repayment period.
• Payments are equal, made monthly, and applied at the end of each monthly period.
• Interest accrues monthly at APR ÷ 12.
• Fees, taxes, insurance, and other charges are not included.

Why HELOC Payments Vary

A home equity line of credit is revolving credit secured by the borrower’s home. Unlike a one-time installment loan, a HELOC generally lets the borrower draw funds up to an approved line limit during a specified draw period. The amount owed changes as money is borrowed, repaid, and possibly borrowed again. The payment depends on the outstanding balance, the rate, the required payment method, and the stage of the line.

Many HELOCs have a draw period followed by a repayment period, but the contract sets the actual terms. During the draw period, some plans require payments that cover interest only; others require principal payments or set a minimum payment. When the repayment period starts, the borrower may have to pay principal and interest over a shorter remaining term. That can make the required payment rise even if the interest rate and balance do not change.

For an interest-only illustration, a $20,000 balance at 8% APR would accrue about $133.33 in one month (20,000 × 0.08 ÷ 12), before fees or daily-balance details. That is not the same as paying off the balance: if no principal is repaid, the $20,000 remains due. The calculator above instead spreads principal and interest across 60 equal payments.

How to Estimate Your Own Payment

For a useful estimate, enter the balance you expect to carry—not necessarily the full credit limit—and a rate and repayment term that match the lender’s terms. If the line’s rate can change, test more than one APR to see how sensitive the payment is. For example, a higher rate generally raises a fully amortizing payment when the balance and term are unchanged.

• Check whether the quoted rate is an APR and whether it is variable.
• Use the actual outstanding balance or planned draw amount.
• Confirm whether the payment is interest-only, a minimum payment, or principal and interest.
• Use the remaining repayment period, not the original draw period, when estimating amortization.
• Ask whether fees or a final balloon payment apply; this calculator does not model them.

Rounding and timing matter. The calculator rounds the monthly payment to cents, while a lender may calculate interest from daily balances and use its own payment rules. A variable rate can also change between statements, so a result based on one APR is a snapshot, not a forecast of every future bill.

Common Payment Surprises

A low payment during a draw period does not necessarily mean the debt is being paid down quickly. If payments cover only interest, the balance can stay level, and a later transition to principal repayment can produce a much larger bill. Borrowing more during the draw period also increases the balance on which interest is charged.

Another misconception is that a HELOC’s payment is determined only by the credit limit. The limit is the maximum available line, not necessarily the amount borrowed. Interest and payment calculations are generally based on amounts outstanding, subject to the agreement’s terms. The exact minimum payment may also include a floor, fees, or other contract-specific provisions that the simple calculator cannot represent.

Frequently Asked Questions

How much is the monthly payment on a $20,000 HELOC?
It depends on the APR, payment structure, and term. At the calculator’s example of 8% APR repaid over five years with equal principal-and-interest payments, the estimate is $405.53 monthly. An interest-only requirement at that rate would be about $133.33 for a month with a $20,000 balance.

Are HELOC payments interest-only?
They may be during part of a line’s term, but not always. The agreement specifies the required payment during the draw period and repayment period. Interest-only payments do not reduce principal.

Can a HELOC payment change?
Yes. A variable APR, changing balance, or move from a draw period to repayment can change the amount due. Check the line agreement and statement for the rate and calculation method that apply.

Does this calculator show my exact minimum payment?
No. It estimates equal monthly payments that repay a balance over a chosen term at an assumed fixed rate. Lender-specific minimums, daily interest calculations, fees, and variable-rate changes are not included.

What happens if I pay only the minimum?
The result depends on how the minimum is calculated. If it covers only interest, the principal may not decline; if it includes principal, payoff time depends on the amount paid and the rate. Consult the account terms for the actual consequences.

This result is an estimate for education, and the lender’s disclosure gives the exact figures.

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in bal | HELOC balance | $ | 20000 | 1 | 100000000
in apr | Interest rate (APR) | % | 8 | 0.01 | 100
in yrs | Repayment term | years | 5 | 0.0833 | 50
out pmt | Estimated monthly payment | $ | round(bal * (apr / 1200) / (1 - (1 + apr / 1200) ^ -(yrs * 12)), 2) | 2
out int | Estimated total interest | $ | pmt * yrs * 12 - bal | 2