Quick Answer: Your Borrowing Limit
To use a home equity loan calculator, you must first know your home's current market value and your outstanding mortgage balance. Lenders typically allow you to borrow up to 80% or 85% of your home's total value, minus whatever you still owe on your primary mortgage.
The Full Calculation with Real Numbers
Your home is likely your largest financial asset. When it appreciates in value, or as you pay down the principal, you build "equity." A home equity loan (often called a second mortgage) allows you to turn that trapped equity into liquid cash for renovations, debt consolidation, or emergency expenses.
Lenders use a strict metric called the Combined Loan-to-Value (CLTV) ratio to protect themselves. Most cap your CLTV at 80%. Let's look at the exact math to determine how much cash you can extract from a $500,000 home.
| Metric | Calculation | Result |
|---|---|---|
| Current Home Value | Determined by a new appraisal | $500,000 |
| Maximum CLTV Allowed (80%) | $500,000 × 0.80 | $400,000 |
| Current Mortgage Balance | What you still owe the bank | -$250,000 |
| Maximum Cash Available | $400,000 max minus $250,000 owed | $150,000 |
In this scenario, even though you have $250,000 in raw equity, the bank will only allow you to borrow $150,000 to ensure there is a 20% equity buffer left in the house in case the market crashes.
What Affects This Number?
Not every borrower will be approved for their maximum CLTV limit. Lenders scrutinize your financial profile before handing over a six-figure check.
1. LTV Limit Variations
While 80% is the industry standard for Combined Loan-to-Value, some aggressive lenders and credit unions will allow you to push to 85% or even 90% CLTV. If you push to 90% on the $500,000 house above, your available cash jumps from $150,000 to $200,000. However, loans over 80% CLTV come with significantly higher interest rates because they are incredibly risky for the lender.
2. Your Debt-to-Income Ratio (DTI)
A home equity loan creates a brand new monthly payment. Just like your first mortgage, the lender will calculate your DTI. If the new home equity loan payment pushes your total monthly debt obligations past 43% of your gross income, the lender will deny the loan or reduce the amount you are allowed to borrow.
3. Appraisal Volatility
You might think your house is worth $500,000 because of Zillow, but the lender will require a formal appraisal. If the appraiser determines the home is only worth $450,000, your 80% maximum drops to $360,000. Subtract your $250,000 mortgage, and suddenly you can only access $110,000 in cash instead of the $150,000 you planned for.
Home Equity Loan vs HELOC vs Cash-Out Refinance
Extracting equity comes in three different flavors, and choosing the wrong one can be financially disastrous.
Home Equity Loan: This is a fixed-rate loan. You receive the $150,000 as one massive lump sum on closing day. You immediately start paying it back with a fixed monthly payment over 10, 15, or 20 years. Best for one-time major expenses like a kitchen remodel or paying off high-interest credit card debt.
HELOC (Home Equity Line of Credit): This functions like a credit card tied to your house. You are approved for a $150,000 limit, but you only draw what you need, when you need it. You only pay interest on the money you actually withdraw. It has a variable interest rate, meaning your monthly payment will fluctuate. Best for ongoing projects where you don't know the exact final cost.
Cash-Out Refinance: Instead of taking out a second mortgage, you completely replace your current primary mortgage with a brand new, larger one. If you have a rock-bottom 3% interest rate on your current mortgage, a cash-out refinance is a terrible idea because it resets your entire loan to today's higher rates. You should only use a cash-out refinance if current rates are lower than your existing rate.
Use Our Free Calculator
Don't apply for a second mortgage blindly. Run the math to see if you have enough equity to fund your project.
Calculate Your Available Equity
Input your estimated home value and current loan balance to see your exact borrowing limit.
Check Your Equity Limit →Frequently Asked Questions
Are home equity loan interest rates higher than primary mortgages?
Yes. Because the home equity loan is a "second mortgage," the primary lender gets paid first if the house goes into foreclosure. To compensate for this elevated risk, lenders typically charge interest rates 1% to 2% higher than standard 30-year fixed primary mortgage rates.
Is the interest on a home equity loan tax deductible?
Under current IRS rules, the interest on a home equity loan or HELOC is only tax-deductible if the borrowed funds are used to "buy, build, or substantially improve the taxpayer's home that secures the loan." If you use the money to pay off credit cards or buy a boat, the interest is not deductible.
Do I have to pay closing costs on a home equity loan?
Yes, though they are usually much lower than a primary mortgage. Expect to pay between 2% and 5% of the total loan amount in closing costs (appraisal, title search, origination fees). Many lenders will roll these fees into the loan balance so you don't have to pay cash upfront.
What happens to a home equity loan if I sell the house?
When you sell the house, both your primary mortgage and your home equity loan must be paid off in full from the proceeds of the sale before you receive any profit. You cannot carry the home equity loan to your next property.