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HELOC Calculator

Interest-only draw + amortizing repayment phase.

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Payment once repayment starts (year 11)

$395.49

/mo
$50,000 at 7.260% · amortizing over 20 years
Draw period
$302.50

interest-only / mo for 10 yrs

Payment jump
+$92.99

1.3× higher / mo

Total interest
$81,218

$36,300 during the draw

The payment shock: during the 10-year draw period the payment is just $302.50/mo. When that ends, the full balance amortizes over 20 years — a 1.3× increase. HELOCs also have variable rates that can rise during your loan.

Try a what-if

Your numbers

$50,000

7.260% APR (variable)

Default 7.26%Bankrate — Current HELOC Ratesas of May 2026

10 years interest-only

20 years amortizing

Next steps

The HELOC Calculator models the two-phase structure of a Home Equity Line of Credit: an interest-only draw period (typically 10 years) then an amortizing repayment period (typically 20 years). When the draw period ends, the monthly payment usually DOUBLES — most HELOC users are caught off guard. This calculator shows both phases clearly so the payment shock isn't a surprise.

How this calculator works

  1. Enter your HELOC balance during the draw period.
  2. Enter the current interest rate (HELOCs adjust monthly with prime — check your statement).
  3. Set the draw period length (10 years is most common) and repayment period (typically 20 years).
  4. Compare the two payment phases. Draw is interest-only and small; repayment is amortizing and much higher. Plan for the transition.

draw_payment = balance × (APR/12) repayment_payment = balance × [r(1+r)ⁿ / ((1+r)ⁿ − 1)]

Two distinct formulas. During the draw period (~10 years), you pay only interest — the balance doesn't decline. When repayment starts, the full balance amortizes over the remaining term (typically 20 years), so the monthly payment is the standard amortization formula. The variable rate (tied to prime) means actual payments can move during the loan.

balance
Outstanding HELOC balance
APR
Annual percentage rate (variable, tied to prime)
r
Monthly rate (APR/12)
n
Number of payments in the repayment phase (years × 12)

Frequently asked questions

What is a HELOC?

A Home Equity Line of Credit. A revolving credit line secured by your home, with two phases: an interest-only 'draw period' (commonly 10 years) and an amortizing 'repayment period' (commonly 20 years). Variable rate tied to prime.

Why is the repayment-phase payment so much higher?

During the draw period you pay only interest, not principal. When repayment starts, the full balance has to be amortized over the remaining term, so the payment jumps. On this calculator's default — $50,000 at 7.26% with a 20-year repayment period — it rises from about $303 to $395 a month, roughly 1.3×. A shorter repayment period makes the jump bigger: over 10 years it nearly doubles (about 1.9×).

When does a HELOC make sense vs a home equity loan?

HELOC: ongoing or unpredictable expense (multi-stage renovation, college tuition over years). Home equity loan: lump-sum need with fixed payments (one-time renovation, debt consolidation). HELOCs have rate risk; home equity loans lock in.

Sources used in this calculator

Reviewed by the Money Scale editorial team. How we source our data

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