HELOC Calculator
This HELOC calculator estimates the home equity line of credit you may qualify for. It also shows what the interest-only payment could be.
By Onias Derilus, Mortgage Capital · NMLS# 1859012 · Last Updated: June 2026
How Your Equity Splits
HELOC rates are typically variable and tied to the prime rate. During the draw period many HELOCs allow interest-only payments. Estimate only.
A home equity line of credit, or HELOC, is a revolving credit line secured by your home. Instead of a lump sum, you draw what you need during a draw period and pay interest only on the balance you use.
Your line size is limited by the combined loan-to-value — the total of your first mortgage plus the HELOC as a share of your home value. Most lenders cap that around 80% to 90%.
These figures are estimates. For neutral, official guidance on mortgage costs and what lenders can charge, see the CFPB's Owning a Home guide.
How to Use This Calculator
- 1
Enter your current home value.
- 2
Enter the balance on your existing first mortgage.
- 3
Set the maximum combined loan-to-value your lender allows.
- 4
Add an illustrative HELOC rate to estimate the line size and the interest-only payment if fully drawn.
The Formula & Assumptions
Max combined = value × max CLTV
Available line = max combined
− first mortgage balance
Interest-only pmt =
drawn balance × rate ÷ 12
The combined loan-to-value limit sets the ceiling on all liens against your home. We subtract your first mortgage from that ceiling to estimate the equity available for a line.
HELOC rates are usually variable and move with the prime rate, so your payment can change over time. Many HELOCs allow interest-only payments during the draw period, then require principal-plus-interest in the repayment period.
Because the line is secured by your home, missed payments put the property at risk. Borrow against equity deliberately and keep a repayment plan in mind.
Frequently Asked Questions
How is a HELOC different from a cash-out refinance?
A HELOC is a second loan that leaves your first mortgage untouched and gives you a revolving line you can draw and repay. A cash-out refinance replaces your entire mortgage with a larger one and hands you a lump sum.
What is the combined loan-to-value limit?
It is the total of all loans against your home divided by its value. If a lender caps combined LTV at 85% and you owe 55% on your first mortgage, you can borrow up to 30% of the value through the HELOC.
Are HELOC payments fixed?
Usually not. Most HELOC rates are variable and tied to the prime rate, so the payment changes as rates move. During the draw period many lines allow interest-only payments, which keeps the minimum low but does not reduce principal.
Can I get a HELOC on an investment property?
Some lenders offer them, but combined LTV limits are typically lower and rates higher than on a primary residence. Reserves and credit requirements are also stricter.
Ready to Turn Your Estimate Into a Real Pre-Approval?
Get a personalized rate quote and pre-approval from a licensed Florida mortgage broker, no obligation.
Rates are illustrative only. APR and payments vary by credit score, loan amount, and market conditions. Subject to credit approval. Not a commitment to lend. NMLS# 1859012. Equal Housing Lender.
It estimates your available home equity line of credit. You also see the interest-only or principal-and-interest payment across the draw and repayment periods.
HELOC Calculator in Florida
A HELOC lets Florida homeowners tap equity without refinancing a low first-mortgage rate, which is valuable for anyone who locked in during the low-rate years. As with any Florida mortgage, documentary stamp and intangible taxes apply to the line, and lenders weigh the area's insurance costs when sizing the credit limit.
How the HELOC Calculator Works
The calculator finds your maximum line by multiplying home value by the allowed combined loan-to-value and subtracting your first mortgage. It then estimates the payment on the amount you draw, often interest-only during the draw period and amortizing afterward.
The HELOC Formula, Explained
Available line = (value × max CLTV) − first mortgage balance
Combined loan-to-value counts your first mortgage plus the HELOC against the home's value, commonly capped around 80% to 90%. The available line is whatever room is left under that ceiling.
HELOC rates are usually variable and tied to an index, so payments can change over time. During the draw period many HELOCs allow interest-only payments; once repayment begins, the balance amortizes and the payment rises.
The Complete HELOC Calculator Guide
A home equity line of credit works like a credit card secured by your house: you are approved for a limit, draw what you need, and pay interest only on the outstanding balance. It is flexible, which makes it popular for renovations and ongoing projects.
The flexibility comes with variable rates. Unlike a fixed cash-out refinance, a HELOC payment can rise if rates climb, and the shift from interest-only draws to full repayment can be a payment shock if you are not prepared for it.
A HELOC shines when you want to keep a low first-mortgage rate intact. Rather than refinancing the whole loan, you add a second lien only on the equity you actually use, often at a lower total cost than a cash-out refinance.
HELOC Calculator FAQ
How is a HELOC different from a home equity loan?
A HELOC is a revolving line you draw from as needed, usually at a variable rate. A home equity loan is a one-time lump sum at a fixed rate. The calculator focuses on the line of credit.
What can I use a HELOC for?
Common uses are home improvements, debt consolidation, and major expenses. Because it is secured by your home, the rate is typically lower than unsecured credit, but your home is collateral.