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HELOC Calculator

Adjust the inputs below. Results update as you type.

How it works

HELOCs have variable rates tied to prime rate + margin. Draw period (typically 10 years): interest-only payments on the amount used. Repayment period (10–20 years): principal + interest on the remaining balance. Maximum line = (home value × LTV limit) − current mortgage balance. LTV limits are typically 80–85%. Rate changes can significantly affect payments—model worst-case scenarios.

Input guidance

  • Use realistic rates from lender or provider quotes instead of headline averages.
  • Model conservative, baseline, and optimistic scenarios before deciding.
  • Include recurring real-world costs (fees, taxes, insurance, maintenance) where relevant.

The formula

A HELOC has a draw period (interest-only or minimum payments on what you borrow at a variable rate) followed by a repayment period where principal and interest amortize.

Worked example

On a $50,000 HELOC at 9%, drawing $20,000 costs about $150/month in interest during the draw period; once repayment begins, payments rise to include principal.

More examples to test

  • Conservative case: use a higher interest rate and lower growth assumptions to stress-test affordability.
  • Optimistic case: use a lower rate with stable income assumptions to compare upside potential.

How to interpret results

Treat this as a planning model, not a final approval tool. Compare at least two scenarios and focus on total-cost and cash-flow trade-offs.

When this can be inaccurate

Results can diverge due to fees, changing rates, tax rules, lender policies, and behavior changes that simplified models cannot fully capture.

Change history

  • July 2026: Quality-reviewed for publication with formula checks and explanatory copy updates.

Site-wide corrections also appear on the corrections log.

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Frequently asked questions

How does a HELOC work?+

It is a revolving credit line secured by your home. You borrow as needed up to a limit during the draw period, then repay over the repayment period.

Is the rate fixed?+

Usually variable, tied to a benchmark like the prime rate, so payments can rise if rates increase — a key risk to plan for.

What can I use it for?+

Commonly home improvements, debt consolidation, or emergencies. Because your home secures it, use it carefully and avoid overborrowing.

How should I use this result?+

Treat it as a planning estimate. Compare at least two realistic scenarios, then confirm with statements, quotes, or a qualified professional before acting.

How often should I refresh assumptions?+

Refresh whenever rates, income, costs, or policy limits change materially, and before making irreversible commitments.

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