Home equity is the portion of a home's value that the owner actually owns outright, calculated as the difference between the home's current market value and the outstanding balance on any loans secured by the property. Understanding how to calculate equity — and how lenders use it — is a foundational step before pursuing a home equity loan, HELOC, cash-out refinance, or even just tracking overall financial progress.
The Basic Equity Formula
The core formula is straightforward:
Home Equity = Current Market Value − Outstanding Mortgage Balance(s)
For example, if a home is currently worth $450,000 and the remaining mortgage balance is $280,000, the homeowner has $170,000 in equity. If there are multiple loans against the property, such as a primary mortgage and a home equity loan, both balances are subtracted from the current value to determine total equity.
Determining Current Market Value
The trickiest part of this calculation is often figuring out what the home is actually worth today, since a home's value isn't fixed the way a loan balance is. Homeowners can get a rough estimate using online automated valuation tools, comparing recent sale prices of similar homes in the area, or, for the most accurate figure, obtaining a professional appraisal. When applying for a home equity loan, HELOC, or refinance, lenders typically require a formal appraisal (or in some cases an automated valuation model) to establish the value used in underwriting, since this figure directly affects how much can be borrowed.
Loan-to-Value (LTV) Ratio
Beyond the dollar amount of equity, lenders frequently talk in terms of loan-to-value (LTV) ratio, which expresses the mortgage balance as a percentage of the home's value:
LTV = Outstanding Mortgage Balance ÷ Current Market Value × 100
Using the earlier example, an LTV would be calculated as $280,000 ÷ $450,000, or about 62%. A lower LTV generally indicates more equity and less risk from the lender's perspective, which is why LTV plays a central role in mortgage insurance requirements (see Private Mortgage Insurance (PMI): A Full Guide) and in loan approval decisions generally.
Combined Loan-to-Value (CLTV)
When a homeowner has more than one loan secured by the property, such as a primary mortgage plus a HELOC or home equity loan, lenders calculate combined loan-to-value (CLTV), which adds together all outstanding balances before dividing by the home's value:
CLTV = (Primary Mortgage Balance + Other Secured Loan Balances) ÷ Current Market Value × 100
Most lenders cap CLTV at a certain threshold, often somewhere around 80% to 85%, when approving new home equity products, meaning the combined total of all loans typically can't exceed that percentage of the home's value. This cap effectively limits how much additional borrowing is available even for homeowners with substantial equity.
How Equity Builds Over Time
Home equity generally grows in two ways: through regular mortgage payments that reduce the loan's principal balance, and through appreciation in the home's market value. Early in a mortgage's term, a larger share of each payment typically goes toward interest rather than principal, meaning equity from payments alone builds more slowly at first and accelerates over time. This amortization pattern can be seen clearly using an amortization schedule calculator, which breaks down how each payment is split between principal and interest across the loan's term.
Home value appreciation, on the other hand, depends on local market conditions and isn't guaranteed; values can also decline, which would reduce equity even if mortgage payments continue as scheduled.
Using Equity Calculations to Access Financing
Once equity is calculated, it becomes the basis for determining how much a homeowner might qualify to borrow through a home equity loan or HELOC, both of which typically allow borrowing up to a percentage of the available equity, subject to the lender's CLTV cap. A comparison of these two options is available in Home Equity Loans vs. HELOCs: Key Differences, along with specific HELOC qualification criteria in HELOC Requirements Explained: What Lenders Want. Equity is also central to a cash-out refinance, where the amount available to cash out is generally limited by the same LTV principles.
Why Tracking Equity Matters
Beyond its role in qualifying for new loans, understanding home equity can help homeowners track overall financial progress, evaluate whether private mortgage insurance might be eligible for removal, and assess how a potential home sale would play out financially after paying off the remaining mortgage balance and any other liens. Before pursuing any equity-based borrowing, it's worth reviewing the broader tradeoffs discussed in Pros and Cons of Borrowing Against Your Home, and using a mortgage payment calculator to see how additional borrowing against that equity would affect monthly obligations.