HELOC Loan Calculator
Estimate your available credit line and monthly payments for a home equity line of credit.
For education only. Actual HELOC terms, variable rates, fees, and qualification rules vary by lender.
What Is a HELOC?
A HELOC (Home Equity Line of Credit) is a revolving credit line secured by your home. Instead of receiving one fixed lump sum, you can borrow as needed up to an approved limit, repay, and borrow again during the draw period.
Most HELOCs have two phases:
- Draw period: You can access funds. Many lenders allow interest-only minimum payments.
- Repayment period: You can no longer draw funds and must repay principal plus interest.
How This HELOC Payment Calculator Works
This tool estimates two things:
- Maximum available HELOC line based on home value, mortgage balance, and max CLTV.
- Monthly payment estimates for both the draw phase (interest-only) and repayment phase (amortized).
It uses a simplified payment model for planning. Real loan offers may include annual fees, minimum draw requirements, teaser rates, and variable-rate adjustments tied to the prime rate.
Key Inputs Explained
1) Home Value
Your lender usually determines this through an appraisal, automated valuation model, or broker opinion. A higher appraised value may increase your available borrowing capacity.
2) Current Mortgage Balance
Lenders look at your total debt on the property. The remaining balance on your first mortgage directly reduces your HELOC eligibility.
3) CLTV Limit
CLTV means Combined Loan-to-Value:
(Mortgage Balance + HELOC Limit) ÷ Home Value
If your lender allows 85% CLTV, your total mortgage + HELOC debt generally cannot exceed 85% of your home value.
4) Interest Rate, Draw Period, and Repayment Period
HELOCs are often variable-rate products. During draw, payments may be lower if interest-only is allowed. During repayment, payments can rise materially because principal must be paid down over a defined timeline.
Example Scenario
Suppose your home is worth $500,000, your mortgage balance is $275,000, and your lender allows 85% CLTV. Your estimated maximum combined debt is $425,000, so your estimated HELOC limit is about $150,000.
If you borrow $100,000 at 8.25%:
- Draw period payment (interest-only estimate): about $687.50/month
- Repayment period payment (20-year amortization estimate): significantly higher, because principal is included
HELOC vs Home Equity Loan
- HELOC: Flexible withdrawals, variable rates common, revolving structure during draw.
- Home equity loan: Lump sum, fixed payment schedule, often fixed rate.
If you need funds in stages (renovation over time, tuition by semester, emergency reserve), a HELOC may be useful. If you want payment predictability, a fixed-rate home equity loan can be easier to budget.
Important Risks to Consider
- Your home is collateral. Missing payments can risk foreclosure.
- Variable rates can increase your monthly payment unexpectedly.
- Interest-only draw payments can hide true long-term repayment cost.
- Over-borrowing against home equity can reduce financial flexibility.
Tips Before Applying
- Compare at least 3 lenders for margin, caps, and annual fees.
- Ask how rate changes are calculated and how often they can adjust.
- Model your budget using a higher “stress test” rate.
- Borrow for value-building goals when possible (e.g., essential home improvements).
- Have a payoff plan before the draw period ends.
Bottom Line
A HELOC loan calculator helps you estimate credit line size and payment ranges before talking with lenders. Use this as a planning tool, then confirm final numbers with official disclosures and personalized quotes.