HELOC Calculator
Estimate line size, draw payments, and rate sensitivity.
What this calculator helps you estimate
A home equity line of credit (HELOC) is a variable-rate revolving line secured by your home. This calculator estimates available equity, line size, and interest-only or amortizing payments.
HELOCs typically have a draw period with interest-only payments, followed by a repayment period where principal is added. Rates are usually variable.
Inputs
HELOC scenario
Program-dependent.
Results
Estimated line & payments
Interpretation
HELOC rates are usually variable. Payments may rise or fall as the index moves.
Rate sensitivity
If your rate changes
| Rate change | New rate | Interest-only payment | Amortizing payment |
|---|---|---|---|
| -2% | 7.25% | $453.13 | $592.78 |
| 0% | 9.25% | $578.13 | $686.90 |
| +2% | 11.25% | $703.13 | $786.94 |
| +4% | 13.25% | $828.13 | $892.07 |
Understand the math
How this calculator works
A HELOC is a revolving line of credit secured by your home, letting you borrow, repay, and borrow again during a set draw period. This calculator estimates your available line size based on combined loan-to-value limits, plus what an interest-only payment on a draw might look like.
Worked example
$450,000 home value, $250,000 existing mortgage balance, 85% maximum combined loan-to-value, drawing $40,000 at an 8.5% variable rate.
- Maximum total debt = $450,000 × 85% = $382,500
- Available line size = $382,500 − $250,000 = $132,500
- Interest-only payment on a $40,000 draw = $40,000 × (8.5% ÷ 12) = $283.33/month
Estimated available line ≈ $132,500; interest-only payment on a $40,000 draw ≈ $283.33/month.
How to read your results
Interpretation guidance
- Your line size is capped by combined loan-to-value across both your first mortgage and the new HELOC — it isn't based on home value alone.
- During the draw period, many HELOCs charge interest only on what you've actually borrowed, not the full line.
- Because HELOC rates are typically variable, this payment will change as market rates move.
- Once the draw period ends, the repayment period usually adds principal to the payment — budget for a step-up.
Deeper answers
More questions about this calculator
How much can I borrow with a HELOC?
Most HELOC programs base your limit on a combined loan-to-value cap — commonly around 80%–90% — applied to your home's value, minus existing mortgage balances. Actual caps vary by lender and credit profile.
How is a HELOC payment calculated?
During the draw period, many HELOCs charge interest only on the outstanding balance. During the repayment period, the balance amortizes over the remaining term, and because rates are variable, payments can change.
Can I pay down and re-borrow?
Yes — that's the core feature of a revolving line, available throughout the draw period, unlike a lump-sum home equity loan.
Does opening a HELOC affect my first mortgage?
No, a HELOC is typically a separate lien; your existing first-mortgage rate and terms stay in place.
Results are estimates for educational purposes only and are not a commitment to lend, loan approval, or official Loan Estimate. Actual rates, payments, costs, taxes, insurance, mortgage insurance, eligibility, and loan terms may vary.
Related calculators
Related loan programs
Answers
Frequently asked questions
How much can I borrow with a HELOC?
Most HELOC programs base your limit on a combined loan-to-value cap — commonly around 80%–90% — applied to your home's value, minus existing mortgage balances. Actual caps vary by lender and credit profile.
How is a HELOC payment calculated?
During the draw period, many HELOCs charge interest only on the outstanding balance. During the repayment period, the balance amortizes over the remaining term. Because rates are variable, payments can change.
Next step
Numbers are helpful. A personalized strategy is better.
Review your scenario with a Vabasso mortgage expert. No pressure, no obligation — just clear guidance for your next move.