Rex says
Money math without the spreadsheet headache. Plug in your numbers and I'll show you exactly where the dollars land.
Try a scenario
Click to load — tweak from there.Inputs
Result
Credit line available
$145,000
Draw-period payment
$425.00
Repayment-period payment
$520.69
Payment increase at conversion
$95.69
Amount drawn
$60,000
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One click, a permanent link with your numbers baked in.
How to use this
- 1Enter home value ($).
- 2Enter mortgage balance ($).
- 3Enter max combined ltv (%).
- 4Enter amount drawn ($).
- 5Enter rate (%).
- 6Enter repayment term (years).
- 7Read your credit line available on the right — it updates as you type.
- 8Hit Share to keep the scenario or send it to someone.
About this calculator
A home equity line of credit usually runs interest-only during the draw period, then converts to fully amortising repayment. The payment jump at conversion catches most borrowers out — this shows both numbers side by side.
Worked example
Using the values the calculator loads with:
Inputs
- Home value: 500000 $
- Mortgage balance: 280000 $
- Max combined LTV: 85 %
- Amount drawn: 60000 $
- Rate: 8.5 %
- Repayment term: 20 years
Results
- Credit line available: $145,000.00
- Draw-period payment: $425.00
- Repayment-period payment: $520.69
- Payment increase at conversion: $95.69
- Amount drawn: $60,000.00
What each field means
Inputs
- Home value ($)
- The home value used in the calculation, measured in $. Starts at 500000 $ so you have a working example on load.
- Mortgage balance ($)
- The mortgage balance used in the calculation, measured in $. Starts at 280000 $ so you have a working example on load.
- Max combined LTV (%)
- The max combined ltv used in the calculation, measured in %. Starts at 85 % so you have a working example on load. Accepted range: 50–100 %.
- Amount drawn ($)
- The amount drawn used in the calculation, measured in $. Starts at 60000 $ so you have a working example on load.
- Rate (%)
- The rate used in the calculation, measured in %. Starts at 8.5 % so you have a working example on load.
- Repayment term (years)
- The repayment term used in the calculation, measured in years. Starts at 20 years so you have a working example on load.
Results
- Credit line available
- Returned as a money amount in US dollars and shown as the headline result. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Draw-period payment
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Repayment-period payment
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Payment increase at conversion
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
- Amount drawn
- Returned as a money amount in US dollars. It recalculates instantly whenever you change an input, so you can compare scenarios without reloading.
FAQ
How does the heloc payment calculator work?
A home equity line of credit usually runs interest-only during the draw period, then converts to fully amortising repayment. The payment jump at conversion catches most borrowers out — this shows both numbers side by side. The underlying maths is: Draw payment = Balance × Rate ÷ 12. Repayment payment amortises the balance over the repayment term.
What do I need to enter?
6 values: home value, mortgage balance, max combined ltv, amount drawn, rate, and repayment term. Each field starts with a sensible default, so you can change one number at a time and watch the result move.
What does the credit line available result mean?
It is returned as a money amount in US dollars and updates live as you edit the inputs, so you can compare two or three versions of a scenario in a few seconds.
Is this calculator free, and do I need an account?
Yes, it's free, and no account is required. Nothing you type is stored on our servers — the maths runs entirely in your browser.
How accurate is the result?
It applies the standard formula exactly, so the arithmetic is precise. Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
Who is this tool for?
It's built for anyone comparing money scenarios before committing — budgeting a payment, sanity-checking a quote, or seeing what a change in rate or term actually costs.
Accuracy and limitations
- Results are estimates before tax, fees, and inflation unless an input explicitly covers them.
- Rates are treated as fixed for the whole period — variable-rate products will drift from this projection.
- This is educational maths, not financial advice. Check anything contractual with the lender or your accountant.
Related tools
Cite this calculator
Writing about this topic? Grab a citation — every link helps keep these tools free.
RevenueLab. (2026). HELOC Payment Calculator. Retrieved from https://www.revenuelab.fyi/toolbox/heloc
<p>Source: <a href="https://www.revenuelab.fyi/toolbox/heloc" target="_blank" rel="noopener">HELOC Payment Calculator — RevenueLab</a> (2026).</p>
Source: [HELOC Payment Calculator — RevenueLab](https://www.revenuelab.fyi/toolbox/heloc) (2026).