HELOC Calculator

Estimate a home equity line of credit amount and compare draw-period and repayment-period payments. This page also keeps the formula, examples, FAQs, and references close by so you can check the result with confidence.

What This HELOC Calculator Helps You Do

Use the HELOC balance, interest rate, and repayment term to estimate monthly payments and borrowing room. Review the formula and examples below if you want to see how the result is derived.

This page is meant to give you a fast answer, but it also helps you double-check the math before you make a decision. Start with the inputs that you already know, run the calculation, and then compare the output with the formula, examples, and FAQs below so you can see whether the answer fits the situation you are modeling.

If the result looks off, the usual causes are a unit mismatch, a missing decimal, the wrong scenario, or a value that needs to be entered as a rate instead of a total. The notes on this page are designed to make those checks easy without forcing you to leave the calculator and search for context elsewhere.

  • Use the calculator first for a quick estimate.
  • Use the formula to understand how the result is built.
  • Use the examples to compare common use cases.
  • Use the references when the answer depends on a standard or assumption.

Common Checks

A quick result is useful, but the best result is one that still makes sense when you look at it a second time. If you are comparing scenarios, try changing one input at a time so you can see which variable has the biggest impact on the final answer. That makes it much easier to spot whether the calculation matches your expectations.

It also helps to keep the context of the problem in mind. A calculator can tell you the math, but you still need to decide whether the input represents a total, a rate, an average, or a category-specific assumption. When in doubt, start with a simple example from the page and scale up from there.

  • Check that every unit matches the rest of the problem.
  • Keep rates, totals, and averages separate.
  • Adjust one variable at a time when testing scenarios.
  • Use the smallest realistic input first, then scale upward.

Scenario Planning

This calculator is especially useful when you want a quick answer before you commit time, money, or effort. Try one baseline input set, then change a single number and compare the result so you can see how sensitive the answer is to that variable.

That makes the page useful for more than just arithmetic. It becomes a small decision aid that helps you compare options, test assumptions, and explain the final number with confidence when you need to share it with someone else.

$
$
$
%
%
years
years
%
$

Result

--

Quick Answer: Use the HELOC balance, interest rate, and repayment term to estimate monthly payments and borrowing room. Review the formula and examples below if you want to see how the result is derived.

How to Calculate HELOC Calculator

  1. Enter your home details: Add the home value and remaining mortgage balance to estimate your borrowing room.
  2. Set the terms: Enter the interest rate, draw period, and repayment period.
  3. Choose the payment mode: Switch between draw-period payment and repayment-period payment.
  4. Review the fees: The result also shows the estimated up-front fee and the available credit line.

HELOC Calculator Formula

HELOC loan amount = (home value x credit limit percent) - mortgage balance
Variable Meaning Unit
home value Current market value of the home $
credit limit percent Portion of home value that can be borrowed %
mortgage balance Outstanding mortgage balance $

Worked Examples

USA - Loan room on a $500k home
  • Home value: $500,000
  • Mortgage balance: $50,000

Result: Available credit line = $350,000

A lender offering 80% of value would leave about $350,000 of borrowing room.

UK - Draw period payment
  • Current HELOC balance: $50,000
  • Interest rate: 6%
  • Draw period: 10 years

Result: Draw period payment = $250

The payment is mostly interest-only while you are in the draw period.

EU - Repayment payment
  • Current HELOC balance: $50,000
  • Interest rate: 6%
  • Repayment period: 20 years

Result: Repayment payment = about $360

Once repayment starts, principal and interest are both included.

GCC - Fee check
  • Current HELOC balance: $75,000
  • Up-front fee: 1%

Result: Up-front fee amount = $750

The fee scales with the balance when you enter a percentage-based fee.

HELOC Reference Chart

The draw period usually means interest-only payments, while repayment includes principal.

Range Meaning Action
Draw period Lower monthly payment Plan ahead for the repayment period.
Repayment period Higher monthly payment Budget for principal and interest together.
80% credit line Typical lender limit Check your lender's actual underwriting rules.
The draw period usually means interest-only payments, while repayment includes principal.
Balance Rate Draw payment Repayment payment
$50,000 6% $250.00 about $555
$100,000 7% $583.33 about $775
$250,000 8% $1,666.67 about $2,093
$350,000 8% $2,333.33 about $2,930

Frequently Asked Questions

A home equity line of credit lets you borrow against your home equity as a revolving credit line.

A common estimate is home value times 80% minus the mortgage balance.

It is the period when you can borrow from the HELOC and often pay interest only.

The balance is paid back with principal and interest, so the monthly payment is usually higher.

Yes. Up-front and annual fees can change the real cost of borrowing.
Planning note: Lender rules, credit limits, and fees vary. Always confirm the real HELOC terms with your lender.

References

Last reviewed: March 30, 2026