HELOC Calculator — Home Equity Line of Credit
Find out how much home equity you can access with a HELOC. Calculate your available credit line, estimate interest-only payments during the draw period, and see full repayment costs.
How to Use This Calculator
- Enter your home's current estimated market value.
- Input your remaining mortgage balance.
- Set the maximum combined loan-to-value (CLTV) ratio your lender allows (typically 80–85%).
- Enter the HELOC interest rate (variable rate, often prime + margin).
- Specify the draw period and repayment period lengths.
- Enter the amount you plan to borrow to see payment estimates.
How Your HELOC Is Calculated
Your maximum HELOC amount is based on your available equity:
Max HELOC = (Home value × Max CLTV%) − Mortgage balance
Draw period payment (interest-only) = Balance × (Annual rate ÷ 12)
Repayment period = Fully amortizing P&I payments on remaining balance
During the draw period, you typically pay only interest on the amount borrowed. Once the repayment period begins, payments include both principal and interest, which significantly increases the monthly amount.
Example Scenarios
Home Renovation — $50,000 HELOC
Home value: $450,000 · Mortgage: $280,000 · CLTV: 80%
Max available: $80,000 · Drawing $50,000 at 8.5%
Draw period payment (interest-only): $354/mo
Repayment period (20-yr): $434/mo
Debt Consolidation — $35,000 HELOC
Home value: $375,000 · Mortgage: $220,000 · CLTV: 85%
Max available: $98,750 · Drawing $35,000 at 9.0%
Draw period payment: $263/mo · vs. credit cards at $700+/mo
Saves ~$437/mo but puts home at risk — use carefully
Emergency Fund Access — $100,000 line
Home value: $600,000 · Mortgage: $350,000 · CLTV: 80%
Max available: $130,000 · Opening $100,000 line (borrowing $0 initially)
Cost: $0/mo until you draw · Annual fee: $50–$100 · Available when needed
Tips for Using a HELOC Wisely
- Only use a HELOC for value-adding purposes (home improvements, education) — not lifestyle spending.
- Budget for payment shock when the repayment period begins (payments can double).
- Consider rate caps — ask your lender about lifetime and periodic rate caps.
- Pay more than the minimum during the draw period to reduce repayment-period payments.
- Keep your CLTV below 80% if possible to maintain a safety buffer in home value.
- Remember: your home is collateral — failure to repay can result in foreclosure.
Frequently Asked Questions
How much can I borrow with a HELOC?
Up to 80–85% of your home's value minus your mortgage balance. A $400,000 home with $250,000 owed allows up to $70,000 at 80% CLTV.
How does a HELOC work?
Two phases: a draw period (usually 10 years) with interest-only payments and flexible borrowing, then a repayment period (usually 20 years) with fully amortizing principal + interest payments.
What are current HELOC rates?
HELOC rates are variable, typically prime + 0.5–2%. In 2025, expect 7.5–10% depending on credit score and LTV. Rates adjust with the prime rate.
Is HELOC interest tax deductible?
Only if funds are used to buy, build, or substantially improve your home. Using HELOC for other purposes (debt consolidation, vacations) is not deductible since 2018.
HELOC vs home equity loan?
HELOC: flexible draws, variable rate, interest-only option. Home equity loan: lump sum, fixed rate, fixed payments. HELOC is better for ongoing needs; home equity loan for one-time expenses where you want payment predictability.