HELOC Draw and Repayment Calculator

Project the full life of a home equity line of credit across both phases. See your interest-only payment during the draw period, the higher amortized payment once repayment begins, the payoff date, and the total interest a HELOC really costs from first draw to final payment.

🏦Real HELOC Scenarios

📝HELOC Terms

Initial draw amount ($)

Balance you borrow at the very start of the draw period.

Additional monthly draw ($, optional)

Extra amount pulled each month during the draw period.

Annual percentage rate APR (%)

Yearly interest rate; most HELOCs are variable.

Draw period (years)

Interest-only window when you can borrow, often 5 to 10 years.

Repayment period (years)

Amortization window after the draw ends, often 10 to 20 years.

Credit limit ($, optional)

Maximum line size; balance is capped here during draws.

Extra principal in draw ($/mo, optional)

Optional principal you pay above interest during the draw.

Result rounding

Controls how currency results are displayed.

Draw interest-only payment $0 per month during draw

Repayment payment $0 fully amortized per month

Lifetime interest $0 draw plus repayment

Total paid $0 payoff in month 0

🔢Payment Snapshot

0xPayment Shock

$0Draw Interest

$0Repay Interest

0Total Months

🗓Year-by-Year Lifetime Timeline

Milestone Year	Phase	Balance	Monthly Payment	Cumulative Interest
-	-	-	-	-

📊Draw vs Repayment Comparison

Feature	Draw Period	Repayment Period	Why It Matters
Can you borrow	Yes, up to limit	No, line closed	Access ends at the switch
Payment type	Interest only	Principal plus interest	Payment jumps sharply
Balance trend	Flat or rising	Falls to zero	No principal cut early
Typical length	5 to 10 years	10 to 20 years	Sets amortization pace
Rate style	Usually variable	Variable or fixed	Adjusts monthly on many lines
Minimum payment	Small, tempting	Large, mandatory	Budget shock risk
Payoff progress	None by default	Steady each month	Debt lingers if only IO paid

📈Interest-Only Payment by Balance and Rate

Balance	6% APR	8% APR	10% APR	12% APR
$25,000	$125	$167	$208	$250
$50,000	$250	$333	$417	$500
$75,000	$375	$500	$625	$750
$100,000	$500	$667	$833	$1,000
$125,000	$625	$833	$1,042	$1,250
$150,000	$750	$1,000	$1,250	$1,500

📐Repayment Payment per $10k Borrowed

Repay Term	6% APR	8% APR	10% APR	12% APR
10 years	$111.02	$121.33	$132.15	$143.47
15 years	$84.39	$95.57	$107.46	$120.02
20 years	$71.64	$83.64	$96.50	$110.11
25 years	$64.43	$77.18	$90.87	$105.32

⚙Formula Breakdown

Monthly rate r = APR / 12Convert the yearly rate to a monthly decimal. An 8.5% APR gives r = 0.085 / 12 = 0.0070833 per month.

Draw payment = Balance × rDuring the draw period the minimum payment is interest only. A $50,000 balance at r = 0.0070833 costs 50000 × 0.0070833 = $354 per month.

Draw balance growthIf you add monthly draws, the balance rises each month and interest accrues on the running balance, capped at the credit limit.

Draw interest totalSum of every month of interest across the draw period. None of it reduces principal unless you pay extra.

Repay payment = B r (1+r)^n / ((1+r)^n - 1)The balance at the end of the draw, B, is amortized over n repayment months using the standard loan payment formula.

Repay interest = (Payment × n) - BTotal interest during repayment equals all payments made minus the principal amortized.

Lifetime interestDraw interest plus repayment interest. This is the true cost of the line beyond the money you borrowed.

Payment shock = Repay payment / Draw paymentHow many times larger the payment becomes when repayment starts; often 2x to 3x.

💡HELOC Cost-Cutting Tips

Pay principal during the draw: Interest-only minimums feel cheap, but they leave the full balance waiting for repayment. Adding even $100 to $200 of principal each month during a 10-year draw can shrink the amortized balance sharply and knock years and thousands of dollars of interest off the repayment phase.

Plan for the payment shock: When the draw ends the payment often jumps 2x to 3x as principal is added. On a $50,000 balance at 8.5%, an interest-only payment near $354 can climb past $1,000 in repayment. Build that higher number into your budget years before the switch so it never catches you off guard.

Maybe you used a HELOC (“home equity line of credit”) to consolidate your debts or fund a renovation project, which is fine, since at first glance this debt seem affordable: those early payments seems low! In reality, there’s two parts to every HELOC; most people only know about the “draw period,” when the principal balance doesn’t change and the payments is low. But then comes the “repayment period“, when the math gets weird and your monthly payment skyrockets.

This means running all phases together in real time. The calculator above does just that, instead of showing what you can afford at only one specific moment. It follows the funds through from the initial pullout to the last payment. It displays the total interest paid over the lifetime of loan and shows the exact date it is fully repaid. In doing so, it addresses the usual error people makes when they only think about short-term cash flow … without considering long-term financial impact of their choice.

How HELOCs Work and How to Save Money

While you’re within the draw period (typically five to ten years), you’ll be able to borrow up to the limit on your line of credit. Typically, you’ll just need to make interest-only payments while in the draw period. How much is that? It’s whatever you owe multiplied by the monthly rate. For instance, if your APR is 8.5 percent and you have a $50,000 balance, you’d pay about $350/month. That sounds like chump change, especially since it won’t touch your principal unless you include additional funds. If you only pay the minimum, you will still owe everything you borrowed by the end of draw period.

And then comes the closing line, at which point it’s time to repay, typically over a ten- to-twenty-year term. At this point, your remaining debt are paid off through a traditional loan formula, so you’re on the hook for interest plus principal. In some cases, that amount jump up by two- or even three-times right from the get-go. If that three-hundred-fifty-dollar monthly payment was manageable before, it might fly into the thousands once you start paying back. This is called payment shock. If you don’t prepare for it, payment shock is one of the biggest sources of budget stress with HELOCs.

Neither side alone tell the story. Interest-only payments omit the unpaid principal, which understates the cost. Repayment payments omit the interest that’s been paid out in the draw. Combined, lifetime interest presents the complete bill. By the time a fifty-thousand-dollar HELOC has been open for a decade under interest-only payments, it can have cost tens of thousands of dollars… All without having touched the principal. It’ll help you see total cost so you know how much to borrow or if you should of repay it early.

Instead of the minimum (which is only interest), pay the principal while in the draw period, even an extra hundred or two hundred dollar a month shrinks the balance that gets amortized later. If you add an extra hundred bucks or two hundred bucks per month now, you’ll shrink the balance that gets amortized after you exit draw. That lowers not only the eventual payment but also the total interest owed.

To maintain low use, borrow far below your limit, so that there won’t be much balance to manage. Most HELOCs is variable-rate, with the potential to change every month; before signing up, it’s good practice to stress-test at a slightly higher rate. The table on the page demonstrates how various rates affects the payment, no math needed!

Last but not least: Budget according to the higher payment (i.e., repayment), not the lower payment (i.e., draw). Use your own calculations to determine what happens if you pay extra principal, how much earlier will this HELOC be paid off? How much less in interest will you repay?

If you think of a HELOC as one big loan with two phases, it’s a mighty weapon. But if you’re stuck thinking about the initial years, then you’ll overspend. Before you sign anything, make sure you have a solid understanding of how a HELOC works from start to finish. So you can enter into the deal with eyes wide open.