Home equity is the share of your home you actually own — what it's worth today minus every lien recorded against it. The formula is one line: Home equity = current market value − all outstanding liens (first mortgage plus any HELOC balance, second mortgage, or other secured lien). On a $500,000 home with a $300,000 first mortgage and no other liens, that's $200,000 of gross equity. But lenders won't let you borrow against all of it, and the number moves every time the market shifts or you make a principal payment. This guide walks the formula, shows a full worked example, explains the difference between gross equity and the "usable equity" your lender will actually let you tap, and lists the specific levers that raise your home's value or shrink your loan balance. If you want the conceptual side — why equity matters and how it grows over the life of the loan — see the companion piece on how home equity actually works.
Key Takeaways
- Home equity equals your home's current market value minus all outstanding liens (first mortgage plus any HELOC balance, second mortgage, or other secured liens) — a one-line subtraction, updated whenever either side moves (CFPB, HELOC toolkit).
- On a $500,000 home with a $300,000 mortgage balance, gross equity is $200,000; usable equity under a typical 80% combined loan-to-value cap is about $100,000.
- U.S. homeowners collectively hold roughly $35 trillion in real-estate equity, per the Federal Reserve's Z.1 household balance sheet (Federal Reserve Z.1).
- You can raise equity from either side of the equation: increase market value (appreciation, cost-effective renovations) or decrease the mortgage (extra principal, refinance to a shorter term, biweekly schedule, recasting).
- The 80% CLTV cap most home equity lenders enforce is a lender norm, not a Fannie Mae rule. Fannie's B2-1.4-01 governs subordinate-financing limits only when a HELOC sits behind a Fannie-eligible first mortgage.
The home equity formula
The formula is one line and doesn't get more complicated than this:
Home equity = current market value − all outstanding liens on the property (first mortgage + HELOC balance + second mortgage / home equity loan + any other secured liens such as tax or contractor liens)
Both sides are point-in-time estimates. The market value changes every time comparable homes sell in your neighborhood. The lien balances change every time you make a payment or draw on a HELOC. Recalculate whenever you're making a decision that depends on the figure — a HELOC application, a PMI removal request, a sell-versus-borrow analysis, a net-worth update.
The lien side is easier to nail down than the value side. Each outstanding lien balance is a precise number — your servicer or HELOC statement shows it to the penny. If your home has only a first mortgage, that's the only line you subtract; if you also have a HELOC (even one with a $0 current draw, count the balance actually owed), a second mortgage, or any other secured lien on title, subtract each one. Your current market value is always an estimate, because your house hasn't sold today. The three common ways to get that estimate are a licensed appraisal (most accurate, $400–$600), a comparative market analysis from a local agent (free, comp-based), or an automated valuation model like Opendoor's free home-value estimate (free, algorithmic). For the full menu of valuation approaches, see how to find your home's current market value.
If the range of reasonable estimates for your home is $485,000 to $515,000 and your mortgage balance is $300,000, your equity is somewhere between $185,000 and $215,000 — narrow enough that the median estimate is usually fine for planning, wide enough to matter if you're right on the edge of an 80% CLTV cap.
A worked example: $500,000 home, $300,000 mortgage
Here is the full arithmetic on a scenario you can adapt to your own numbers.
Step 1 — write down the inputs.
- Current market value: $500,000
- Outstanding first-mortgage balance: $300,000
- Any HELOC balance, second mortgage, or other secured lien: $0 (in this example)
Step 2 — subtract every lien from the value.
- Gross equity: $500,000 − $300,000 − $0 = $200,000
Step 3 — convert to a percentage if you're thinking about PMI or CLTV.
- Equity as a share of value: $200,000 / $500,000 = 40% equity
- Equivalently, your loan-to-value (LTV) is 60% ($300,000 / $500,000).
That's it. The whole calculation is one subtraction and one division.
Now watch how the number moves when one input changes. If your local market softens and comps suggest your value dropped to $475,000, gross equity drops to $175,000 (about 36.8% equity, 63.2% LTV) — even though you didn't miss a payment. If the market held at $500,000 but you paid the balance down to $280,000, gross equity climbs to $220,000 (44% equity, 56% LTV). Your equity can rise or fall by tens of thousands of dollars without any action on your part — which is why "recalculate before you decide" matters more than the formula itself.
Gross equity vs usable equity
The $200,000 figure above is your gross equity — the arithmetic answer. Your usable equity is what a lender will actually let you borrow against, and it's a smaller number.
Most home equity lenders cap combined loan-to-value (CLTV) at 80%. CLTV means your first mortgage balance plus any new second-lien balance can't exceed 80% of the appraised value. On a $500,000 home, that ceiling is $400,000. Subtract your existing first mortgage of $300,000 and the room left for a home equity loan or HELOC is $100,000 — half of your gross equity.
| Item | Amount |
|---|---|
| Home value | $500,000 |
| 80% CLTV ceiling ($500,000 × 0.80) | $400,000 |
| Existing first-mortgage balance | $300,000 |
| Usable equity ($400,000 − $300,000) | $100,000 |
| Gross equity (for reference) | $200,000 |
A few practical points on the 80% number.
It's a lender norm, not a rule. Some portfolio HELOC lenders go to 85% or 90% CLTV for borrowers with 720+ FICO and low debt-to-income ratios — usually at a rate premium. Others hold the line at 75% or 80% regardless of borrower quality. HELOCs and home equity loans are held on lenders' own balance sheets, not sold to Fannie Mae or Freddie Mac, so each institution sets its own CLTV/DTI/FICO cutoffs.
Fannie Mae's B2-1.4-01 governs subordinate-financing limits only when a HELOC sits behind a Fannie-eligible first mortgage. Those rules are not the source of the 80% cap most home equity lenders enforce. Don't repeat the common myth that "Fannie caps CLTV at 80%" — Fannie doesn't buy HELOCs.
The 80% cap is a maximum, not a target. In practice you may borrow less because the appraisal comes in soft, or because closing costs (2–5% of the line) eat into the amount worth drawing. See what a home equity loan is and how it's priced and how a HELOC's draw and repayment periods work for the product mechanics.
How much equity do most Americans have?
To put an individual balance in context: U.S. households collectively hold roughly $35 trillion in real-estate equity as of the most recent Federal Reserve Z.1 release (Federal Reserve Z.1, household balance sheet). That number is the aggregate of every homeowner's gross equity across owner-occupied and second-home real estate.
Two forces have compounded that balance. First, appreciation — FHFA's national House Price Index has run well above long-run averages over the past decade. Second, amortization — the median U.S. homeowner has now been in their home about 13 years per the National Association of Realtors, long enough for the principal portion of each payment to have meaningfully cut the original balance. The two forces work on opposite sides of the equity formula (numerator up, denominator down), which is why balances have grown even for owners who did nothing intentional to build equity.
How to raise the market value (numerator)
Two categories of levers move the numerator: passive market appreciation and active homeowner investment.
Market appreciation happens whether you do anything or not. Long-run national appreciation has averaged roughly 3–4% per year, higher in supply-constrained metros. The FHFA House Price Index publishes quarterly numbers at the national, state, and metro level — worth checking against your ZIP before you assume your home has tracked the national trend.
Cost-effective renovations are the active lever. Per Zonda's annual Cost vs. Value report, the highest-ROI categories are exterior curb-appeal projects (garage door, siding, entry door), minor kitchen refreshes, and minor bathroom remodels. See renovations that typically add the most value for the full comparison.
The math on renovations is asymmetric in a way most homeowners underestimate. Appreciation happens on the full market value: a 4% year on a $500,000 home adds $20,000 at zero out-of-pocket cost. Renovations return less than 100% of cost in appraised value: a $30,000 kitchen refresh typically appraises for $22,000–$27,000 more, netting a loss on the equity ledger relative to cost. The reason to renovate is livability plus long-run resale positioning, not a dollar-for-dollar equity build. Swimming pools outside the Sun Belt, high-end custom kitchens in mid-tier neighborhoods, and hyper-personal finishes are worth doing for how you live in the home — not to raise equity.
How to decrease the mortgage balance (denominator)
Four levers move the denominator, each with a different liquidity trade-off.
Extra principal payments. Every dollar of extra principal reduces the mortgage-balance side of the formula by exactly one dollar. On a 30-year fixed, an extra $100/month applied to principal shaves several years off the term and tens of thousands off total interest. The catch: that money is now illiquid. You can't un-pay a mortgage payment without borrowing against the equity you just built.
Biweekly payment schedule. Splitting your monthly payment into two half-payments every two weeks results in 26 half-payments per year — the equivalent of 13 full payments instead of 12. That extra payment goes straight to principal, taking roughly 4–6 years off a 30-year term. Confirm with your servicer that they apply half-payments as principal reductions rather than holding them as unapplied credits, which negates the benefit.
Refinance to a shorter term. Moving from a 30-year to a 15-year mortgage sends a larger share of each payment to principal because you're amortizing the same balance over half the time. The monthly payment rises significantly in exchange. The 15-year rate is also typically 0.5–1.0 percentage points lower than the 30-year — see the current spread on the Freddie Mac Primary Mortgage Market Survey. A refinance resets closing costs (2–4% of loan amount) that need to be recovered in payment savings.
Recasting. A recast is a one-time principal payment plus a servicer re-amortization at the same rate and remaining term, which lowers the monthly payment for the rest of the loan. Fees are typically $200–$500 versus a full refinance's thousands. Conventional loans usually allow recasts; FHA and VA loans generally do not. Worth considering when you receive a lump sum (bonus, inheritance, home-sale proceeds) and want lower fixed housing costs without refinance closing costs.
None of these levers is universally worth it. All four trade liquidity for equity, and depending on your rate and job stability, holding cash may be the better trade.
When to recalculate
The equity number is only useful if it's current. A reasonable cadence:
- Once a year, minimum — as part of an annual net-worth or financial-plan update.
- Within 12 months of a refinance, HELOC, or home equity loan application — the lender will use their own appraisal, but knowing your own estimate first prevents surprises.
- When local prices have moved noticeably — either direction. A local median drop of 5% is a $25,000 swing on a $500,000 home.
- When you're weighing sell vs. borrow — the equity number sets the ceiling on both paths.
- Before requesting PMI removal — you need to know whether you've crossed the 80% or 78% LTV threshold before you file the request.
For the market-value input, an automated valuation model like Opendoor's free home-value estimate is a fine starting point — usually accurate enough for a first pass. When the number will drive a real decision, pair it with a comparative market analysis from an agent or a licensed appraisal.
