How to use the home equity loan calculator
- Enter your current home value based on a recent appraisal or market estimate.
- Type in your outstanding mortgage balance, which you can find on your latest statement.
- Set the maximum LTV percentage your lender allows, typically between 80% and 90%.
- Provide the expected interest rate and loan term in years.
- Read the results to see your available equity, combined LTV and estimated payment.
How available equity is calculated
The core formula behind any home equity calculator is straightforward. First, multiply your home value by the maximum loan-to-value ratio the lender permits. Then subtract your current mortgage balance. The remainder is the most you can borrow.
Available Equity = (Home Value x Max LTV) - Mortgage Balance
For example, if your home is worth $400,000 and the lender allows an 80% LTV, the maximum total debt secured by the property is $320,000. Subtract a $250,000 mortgage balance and you have $70,000 in borrowable equity.
Understanding combined LTV
Combined loan-to-value (CLTV) measures all loans secured by your property against its appraised value. When you take out a home equity loan, the CLTV includes both your first mortgage and the new loan.
CLTV = (Mortgage Balance + Home Equity Loan) / Home Value
Lenders use CLTV to gauge risk. A higher CLTV means less cushion if property values drop. Most conventional lenders cap CLTV at 80%, though some programs extend to 85% or 90%. Staying below these thresholds often secures better rates.
Fixed payment formula
A home equity loan typically carries a fixed interest rate and a set repayment schedule. The payment is computed using the standard amortization formula:
P = L x [r(1+r)^n] / [(1+r)^n - 1]
Where L is the loan amount, r is the monthly interest rate (annual rate divided by 12), and n is the total number of months. For a $70,000 loan at 7.5% annual interest over 15 years (180 months), the monthly rate is 0.00625. Plugging that in yields a payment of roughly $648.89.
If you need to model variable-rate scenarios or explore how extra payments shorten a term, a general loan calculator handles those variations. For first-mortgage comparisons, try the mortgage calculator.
Common reference values
The table below shows how different LTV limits affect borrowable equity for a $400,000 home with a $250,000 existing mortgage.
| Max LTV | Max Total Debt | Available Equity | Resulting CLTV |
|---|---|---|---|
| 75% | $300,000 | $50,000 | 75% |
| 80% | $320,000 | $70,000 | 80% |
| 85% | $340,000 | $90,000 | 85% |
| 90% | $360,000 | $110,000 | 90% |
Even a five-point shift in the allowed LTV changes the available funds significantly. Always confirm the exact limit with your lender before applying.
Practical uses for home equity
Borrowers commonly use a home equity loan for large, one-time expenses where a predictable payment matters. Typical uses include major home renovations, consolidating high-interest credit card balances into a single lower-rate obligation, or funding tuition.
Because the loan is secured by your property, rates are usually lower than unsecured personal loans. However, defaulting puts your home at risk. Before borrowing, compare the total interest cost against alternatives. If you are evaluating long-term wealth effects, an inflation calculator helps show how future dollars compare to today's purchasing power.
Edge cases and common mistakes
Several pitfalls trip up borrowers using a home equity calculator for the first time:
- Overestimating home value. Use a professional appraisal or a conservative automated valuation. Inflating the value artificially increases your perceived equity but will not pass underwriting.
- Ignoring closing costs. Origination fees, appraisal charges and title insurance reduce your net proceeds. Factor in 2% to 5% of the loan amount for costs.
- Confusing HELOCs with home equity loans. A home equity loan disburses a lump sum at a fixed rate. A HELOC works like a revolving credit line with a variable rate. This tool calculates the lump-sum version.
- Negative equity. If your mortgage balance exceeds the allowable LTV threshold, the result is zero or negative borrowable equity. You cannot take out a home equity loan until you pay down the balance or the property appreciates.
Method and sources
Worked example: a $400,000 home, $250,000 mortgage and an 80% limit leave $70,000.00 to borrow. At 7.5% over 15 years the fixed payment is $648.91, total interest is $46,803.56, and the combined loan-to-value ends at 80%.
Method: available equity = value x limit - mortgage; payment from the amortization formula. Lenders set their own limits (often between 80% and 90% combined), cap loan sizes by credit and income, and charge closing costs that are not included here. Treat the result as a ceiling, not an approval.
Worked examples
| Example | Input | Result |
|---|---|---|
| Typical borrower at 80% LTV | Home value ($): 400000; Current mortgage balance ($): 250000; Maximum LTV (%): 80; Interest rate (%): 7.5; Loan term (years): 15 | Available equity: $70,000.00; Combined LTV: 80%; Estimated payment: $648.91; Total interest: $46,803.56; Total paid: $116,803.56 |
| Higher LTV allowance (90%) | Home value ($): 350000; Current mortgage balance ($): 200000; Maximum LTV (%): 90; Interest rate (%): 8; Loan term (years): 10 | Available equity: $115,000.00; Combined LTV: 90%; Estimated payment: $1,395.27; Total interest: $52,432.08; Total paid: $167,432.08 |
| Small loan, short term | Home value ($): 500000; Current mortgage balance ($): 100000; Maximum LTV (%): 80; Interest rate (%): 6.5; Loan term (years): 5 | Available equity: $300,000.00; Combined LTV: 80%; Estimated payment: $5,869.84; Total interest: $52,190.67; Total paid: $352,190.67 |
| No existing mortgage | Home value ($): 250000; Current mortgage balance ($): 0; Maximum LTV (%): 85; Interest rate (%): 7; Loan term (years): 20 | Available equity: $212,500.00; Combined LTV: 85%; Estimated payment: $1,647.51; Total interest: $182,902.46; Total paid: $395,402.46 |
FAQ
What is a home equity loan calculator?
It is a tool that estimates how much money you can borrow against your home. It subtracts your current mortgage balance from the maximum debt your lender allows based on a percentage of your home's value.
What LTV do most lenders require?
Most conventional lenders cap the combined LTV at 80%. Some government-backed or specialized programs allow up to 85% or 90%, but higher LTVs usually come with stricter credit requirements or higher rates.
Is the interest rate fixed or variable?
A traditional home equity loan has a fixed interest rate and a fixed payment schedule. If you want a variable rate and draw-on-demand access, you are looking for a home equity line of credit (HELOC), which uses a different structure.
Can I use this tool if my mortgage is paid off?
Yes. Enter zero for the current mortgage balance. Your available equity will simply be the home value multiplied by the maximum LTV percentage.
Does this calculator include closing costs?
No. The figures shown represent gross borrowable amounts and principal-and-interest payments. Closing costs such as appraisal fees, origination charges and title insurance will reduce your net proceeds.
What happens if my available equity is negative?
A negative result means your current mortgage balance already exceeds the lender's maximum LTV threshold. You would need to pay down your mortgage or wait for your home to appreciate before qualifying for a home equity loan.
Why does the result show the maximum, not what I should borrow?
The tool answers "how much could the equity support at this limit". Borrowing the maximum raises your combined LTV to the limit and the payment you must carry for the full term, so most people borrow less.