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HELOC calculator

Check how much you can borrow against your home and what the payments look like — including the jump when the draw period ends.

Home value
Mortgage balance
Amount to borrow
Interest rateAPR
%

You could borrow up to

$125,000

Home equity $200,000 · CLTV after borrowing 70%

Payment during draw (10 yrs, interest-only)
$333.33
Payment during repayment (20 yrs)
$418.22
Payment increase at repayment
+$84.89
Total interest (if fully drawn)
$90,372

HELOC rates are usually variable (prime + margin), so payments change when rates move.

Max line$125,000

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The HELOC borrowing formula

Max line = home value × max CLTV − mortgage balance. Draw-period payment = balance × rate ÷ 12. Repayment payment = the balance amortized over the repayment years at the current rate.

Assumptions

  • Full amount drawn at the start and held through the draw period with interest-only payments, then repaid over the repayment period at the same rate.

Frequently asked questions

How much can I borrow with a HELOC?+

Lenders typically allow a combined loan-to-value (CLTV) of 80–90%. Multiply your home value by that percentage and subtract your mortgage balance: a $500,000 home with $300,000 owed at 85% CLTV allows about $125,000.

How are HELOC payments calculated?+

During the draw period (often 10 years) most HELOCs require interest-only payments on what you've borrowed. After that, the balance is repaid with principal and interest over the repayment period (often 20 years), so the payment rises sharply.

HELOC or home equity loan?+

A HELOC is a revolving line with a variable rate — good for expenses spread over time. A home equity loan is a lump sum with a fixed rate and fixed payments — better when you need a set amount and want predictable payments.

Is HELOC interest tax-deductible?+

Only when the money is used to buy, build or substantially improve the home securing it, and only if you itemize deductions. With the 2026 standard deduction at $16,100 single / $32,200 joint, many borrowers won't benefit.

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Last reviewed October 15, 2026. Calculator version 1.0.0. Results are estimates for educational purposes, not financial, tax or lending advice. How we check our numbers.