How to use the HELOC Calculator
The HELOC calculator shows your available credit line and the interest-only payment on what you draw.
What you need to enter
- Home value ($)
- Mortgage balance ($)
- Max combined LTV (%)
- HELOC rate (%)
- Amount drawn ($)
The formula
Credit line = home value × LTV limit − mortgage. Interest-only payment = drawn amount × annual rate ÷ 12.
Worked example
Using the default values in the calculator:
- Home value ($): 450000
- Mortgage balance ($): 250000
- Max combined LTV (%): 85
- HELOC rate (%): 9
- Amount drawn ($): 40000
| Available credit line | $132,500.00 |
| Interest-only payment on draw | $300.00 |
| Remaining available | $92,500.00 |
Tips for better results
- HELOC rates are often variable.
- Plan for repayment after the draw period.
Common mistakes to avoid
- Using it for long-term spending.
- Ignoring payment increases.
Please note: Calculators and guides give general estimates, not financial, tax or investment advice. Real offers depend on your lender, location and personal situation. See our Disclaimer.