HELOC Payment Calculator

A HELOC (Home Equity Line of Credit) lets you borrow against your home's equity — the difference between what your home is worth and what you still owe. Unlike a one-time loan, a HELOC behaves like a credit card secured by your home: you are approved for a limit, you draw only what you need, and you pay interest only on what you actually use. That flexibility is the appeal, and it is also the risk — because the repayment rigour is entirely your own.

Two phases, two very different payments

A typical HELOC runs in two phases:

During the draw period you can often pay only the interest:

Monthly interest = balance × (annual rate ÷ 12)

For $50,000 drawn at 8.5%:

Monthly interest = 50,000 × 0.00708 ≈ $354/month

The balance stays flat — you are not paying down principal. This is the number most people see and think "that is cheap". It is the rent on the money, not the repayment.

Amortized payments

When the repayment period begins (or if you choose to amortize during draw), your payment covers principal and interest over the term:

Payment = P × r ÷ (1 − (1 + r)⁻ⁿ)

With r = monthly rate and n = months. Same $50,000 over 10 years: roughly $620/month. The jump from $354 to $620 is gentle; it becomes brutal if you drew on the line carelessly during years of interest-only payments.

Why HELOC rates feel low (and can bite)

HELOCs use variable rates tied to a benchmark (like SOFR or a bank's base rate). The teaser rate can rise sharply. Consider a $50,000 balance at 5% — interest of $208 a month — that re-prices to 9% — $375 a month — after the lender's index moves. Borrowers who stretched at the teaser rate get squeezed in a rising-rate cycle. Because it is secured by your home, falling behind on a HELOC puts the house at risk — the interest paid is just the entry fee; the collateral is the real exposure.

HELOC vs the alternatives

• Home equity loan — a fixed lump sum at a fixed rate, amortizing from day one. Better for a defined one-time expense; no temptation to re-draw.
• Cash-out refinance — replaces your whole mortgage with a larger one. Good for large needs, but resets your entire home loan and its rate.
• HELOC — best for ongoing, uncertain expenses (home renovations staged over a year, tuition billed per term) where you want to draw and repay as you go.

Practical guardrails

• Borrow only for things that build value — a kitchen remodel typical for the neighborhood — not for consumption.
• Calculate the fully amortized payment on your expected draw, not the interest-only teaser, and check it against your budget before drawing the first dollar.
• Read the rate-cap clause. Most HELOCs cap how much the rate can rise per adjustment, but the caps can be high in absolute terms.

This calculator is an estimate. Actual HELOC terms — draw period, rate caps, and payment structure — vary by lender.