HELOC Tools

HELOC Payment Calculator Draw & repayment phases, with extra payments

Calculate your HELOC payments

Understanding HELOC draw and repayment phases

What this HELOC payment calculator does

A home equity line of credit (HELOC) works differently from a fixed loan, and a standard mortgage calculator gets it wrong. This HELOC payment calculator models both phases of a typical HELOC: the interest-only draw period and the fully amortized repayment period. Enter your current balance, APR, the length of each phase, and any extra monthly payment you plan to make. The calculator returns the payment required in each phase, your projected payoff date, total interest costs, and a year-by-year amortization summary so you can see the balance fall over time.

Draw period vs. repayment period

Most HELOCs are split into two phases. During the draw period — commonly 10 years — you can borrow against your credit line, repay it, and borrow again. Your required payment is usually interest-only: you pay the interest that accrued on your balance that month, and the principal stays untouched unless you choose to pay more. Because interest is charged on your current balance, the interest-only payment rises when you draw more and falls when you pay the balance down.

When the draw period ends, the repayment period begins — commonly 20 years. You can no longer borrow, and the outstanding balance is amortized: your fixed payment now includes principal plus interest, calculated so the balance reaches zero at the end of the term. This is the phase that surprises many borrowers, because the required payment can jump sharply. A $50,000 balance at 6% APR costs about $250 per month interest-only, but about $358 per month once amortized over 20 years. Planning for that jump before it happens is one of the smartest moves a HELOC borrower can make.

How HELOC payments are calculated

The interest-only payment is simple: current balance multiplied by APR divided by 12. The repayment payment uses the standard amortization formula — the fixed payment that pays the remaining balance and interest exactly over the repayment term. This calculator applies the same convention most lenders use: each month during the draw period you owe the interest on your current balance, and any extra amount you pay reduces principal immediately, which lowers the next month's interest charge. At the end of the draw period, whatever balance remains is amortized over your repayment term.

How extra payments shorten your HELOC

Extra payments are powerful because HELOC interest is charged on your current balance, not on an original loan amount. Every extra dollar you pay removes a dollar of principal, and every dollar of principal removed stops accruing interest for the rest of the life of the line. Paying an extra $100 or $200 per month during the draw period compounds in your favor: your required interest-only payment shrinks as the balance falls, and the smaller remaining balance means a smaller — and shorter — repayment payment later. Use the extra payment field in this HELOC calculator with extra payments to see your new payoff date, the months saved, and the total interest saved compared with paying only the required amounts.

Tips for using this calculator

Use your most recent statement balance and note whether your APR is variable — if it is, results at today's rate are a snapshot, not a guarantee. Try several extra payment amounts to find a plan that fits your budget, and remember that paying during the draw period has the biggest effect because it works over more months. If your repayment-phase payment looks unaffordable, use these numbers to build a paydown plan now rather than facing the payment shock later.

HELOC payment FAQ

How is the interest-only HELOC payment calculated?

During the draw period, most lenders require an interest-only payment equal to your current balance multiplied by your APR divided by 12. On a $50,000 balance at 6% APR, the monthly interest-only payment is about $250. Because the payment is based on your current balance, it falls whenever the balance falls.

What happens to my HELOC payment when the draw period ends?

When the draw period ends, the repayment period begins and your outstanding balance is amortized over that term. Your required payment jumps from interest-only to principal plus interest, which is usually significantly higher. A $50,000 balance at 6% APR amortized over 20 years requires a payment of about $358 per month.

How do extra payments affect my HELOC?

Extra payments reduce your principal immediately. Interest is charged on your current balance, so every extra dollar lowers all future interest charges. This shortens the time to pay off the line and can save thousands of dollars in total interest, especially if you start extra payments during the draw period.

Does making extra payments during the draw period lower my required payment?

Often yes during the draw period: because the interest-only payment is recalculated from your current balance, a smaller balance means a smaller required payment. During the repayment period the required payment is fixed, so extra payments do not lower it — they shorten the payoff term instead. Check your loan agreement, since some lenders apply their own recalculation rules.

Is this HELOC payment calculator accurate for my actual loan?

This calculator uses the standard amortization and interest-only formulas that most HELOCs follow, so it is a reliable planning estimate. Your actual statement may differ because of variable rate adjustments, fees, day-count conventions, or lender-specific payment rules. Use the results for budgeting and comparison, and confirm details with your lender.