HELOC Payment & Draw Period Calculator

Draw Period vs. Repayment: The Two-Phase Reality

Your HELOC statement shows $83 due this month. Easy. Then year six arrives and suddenly you owe $847. Same balance, same rate, but the draw period ended and repayment began. That's payment shock, and it catches thousands of homeowners off guard every year. This HELOC payment calculator shows you both numbers before you sign.

How much does a HELOC payment jump when the draw period ends? Commonly 40 to 100 percent, because you stop paying interest only and start paying down principal on the same balance. A $65,000 balance at 8.25% that runs $447 a month interest-only becomes about $631 once a 15-year repayment begins. Both numbers show here before you sign.

A Home Equity Line of Credit works in two phases. During the draw period (typically 5-10 years), you borrow as needed and make interest-only payments. The balance stays flat. When the draw period ends, the repayment period kicks in (typically 10-20 years)—no more borrowing, and payments now include principal. The jump can be 40-100% higher.

Enter your HELOC balance, rate, and terms. The calculator displays your draw-period payment, repayment-period payment, and exactly how much your monthly cost increases. You can also model rate increases to see worst-case scenarios.

Three Factors That Determine Your Payment

Your drawn balance: Interest-only payments scale directly with your balance. $50,000 at 8% costs $333/month. $100,000 at 8% costs $667/month. Only borrow what you need.

The interest rate: Most HELOCs are Prime + a margin (typically 0.5-2%). When the Federal Reserve raises rates, your payment rises too. A 1% rate bump on $75,000 adds $62.50/month during the draw period.

Repayment term length: Shorter repayment periods mean higher monthly payments but less total interest. $100,000 at 8% over 10 years costs $1,213/month. Over 20 years: $836/month—but you'll pay $100,000 more in total interest.

Payment Shock, Walked Through One Real Draw

The Hendersons drew $65,000 from their HELOC for a kitchen remodel at 8.25%, with four years left in the draw period and a 15-year repayment term waiting behind it. Right now they pay interest only: $447 a month. It feels affordable, which is exactly the trap.

When the draw period closes, the balance starts amortizing over 15 years and the payment jumps to $631. That's a 41% increase overnight, on the same debt at the same rate, because nothing changed except the calendar. Across the life of the loan they'll hand the lender $48,580 in interest.

Then there's the part the payment table doesn't show: the rate isn't fixed. HELOCs float with the prime rate, so if the Hendersons' rate ticked up even a point before repayment began, that $631 would land higher still. A variable rate stacked on top of the amortization switch is how a comfortable draw becomes a payment nobody planned for.

The fix is dull and it works. Start paying the $631 now, four years early. The extra $184 a month goes straight to principal, so the balance is smaller when repayment hits and the eventual payment comes in lower than it otherwise would. If the rate risk keeps you up at night, converting to a fixed-rate home equity loan trades the uncertainty for a known number, and refinancing into a fresh HELOC is possible too, though it just winds the same clock back to the start. When the interest-only setup is a fixed-rate loan rather than a revolving line, the interest-only loan calculator models the same jump when principal kicks in.

What Can Go Wrong With HELOCs

Payment shock timing: The repayment transition often hits when you least expect it. Many people open HELOCs in their 40s-50s; repayment might start right as retirement approaches. Plan the timeline.

Rate volatility: From 2022-2023, Prime Rate jumped from 3.25% to 8.5%. A HELOC that cost $300/month suddenly cost $500+. Variable rates cut both ways, but they rarely drop as fast as they rise.

Your home is collateral: Unlike credit cards, a HELOC is secured by your house. Falling behind can lead to foreclosure. Only use HELOCs for needs that justify that risk—not vacations or everyday spending.

Treating it like free money: The easy access during the draw period tempts people to overborrow. Every dollar drawn increases your eventual repayment payment. The low interest-only payment masks the true commitment.

Balloon payment HELOCs: Some older HELOCs require the full balance due at the end of the draw period instead of converting to repayment. Check your agreement. If you have a balloon HELOC, refinancing is mandatory—start planning years in advance.

How the Calculator Models Your Payments

Draw period: Uses your current balance and rate to calculate interest-only payments. If you enter planned additional draws, those are added to the balance.

Repayment period: Takes the balance at the end of the draw period and amortizes it over your repayment term using standard loan formulas.

Rate scenarios: If you enter an assumed future rate, the calculator recalculates both phases at that rate so you can see worst-case payments.

Assumptions: Fixed rate during each scenario (actual HELOC rates fluctuate), minimum payments only (no extra principal), and standard monthly compounding.