What Is Equity?

Picture a house purchased in January 2015 for $320,000. The buyer put 20 percent down ($64,000), borrowed the remaining $256,000, and moved in. On day one, their equity in that home was exactly $64,000: the value of the property minus the outstanding debt. A decade later, if the home is worth $480,000 and the remaining mortgage balance is $190,000, that equity has grown to $290,000, a gain of $226,000 they never had to write a separate check for. That is what equity does. It accrues on two separate tracks at once, and understanding both is the foundation of how homeownership builds wealth.

The idea in plain words

Equity is the portion of an asset's value you actually own, after you subtract the debt secured against it. The formula is simple: equity equals market value minus outstanding debt.¹ What makes it powerful is that the number moves even when you are doing nothing beyond making your regular payment each month.

The Consumer Financial Protection Bureau (CFPB) defines home equity as the difference between what your home is worth and what you owe on your mortgage.¹ That gap is the piece you could walk away with if you sold the property today and paid off the loan in full. It is also the piece lenders look at when you want to borrow against the home later.²

Walk through the math: two forces, one number

Let's start with how the machine actually works. Home equity builds through two distinct forces: mortgage paydown and appreciation. They are independent of each other, and on a long enough timeline, both compound in your favor.

Take the example from the top. A $256,000 mortgage at a 30-year fixed rate around 3.7 percent (a realistic rate for early 2015) produces a monthly principal-and-interest payment of roughly $1,177.³ In year one, most of that payment is interest: the loan amortizes slowly at first. By the end of year one, the balance has only dropped to about $249,000. But the home may have appreciated from $320,000 to $336,000 if prices rose a modest 5 percent that year. Equity: $336,000 minus $249,000 = $87,000, up from the original $64,000 even though the loan paydown alone was modest.

Now let the same numbers run forward. By the end of year five, the remaining balance is roughly $228,000. If the home appreciated at 5 percent per year since purchase, it is worth about $408,000. Equity: $180,000. By year ten, the balance is around $197,000 and a home that kept growing at the same rate is worth approximately $521,000, for equity of $324,000. The paydown and the appreciation work simultaneously, and neither one requires a decision. They just run.

The Federal Reserve's Financial Accounts of the United States tracks aggregate homeowner equity across the country. As of 2024, American households held over $32 trillion in home equity, the largest single store of wealth for most middle-class families.⁴ That number is not an accident. It is the product of millions of mortgages being paid down month after month while property values rise.

Change one thing: how equity shifts with price and balance

The sensitivity here is worth seeing in a table, because the relationship is not perfectly linear, particularly early in the loan.

A $20,000 drop in home value (the fourth row compared to the first) cuts equity by $25,000, because the balance did not fall with the price. This is why homes purchased with minimal down payments are vulnerable early in a downturn: the equity cushion is thin, and a modest price correction can push a borrower into a negative-equity position, where the outstanding debt exceeds the market value. That scenario is sometimes called being "underwater" on the mortgage.

If you want to run your own numbers with a real payment schedule, the mortgage calculator at /tools/mortgage will show you how the balance and equity evolve month by month.

The second meaning: equity in a company

Now shift to where this same concept shows up in a completely different setting. When you buy shares of stock, you are purchasing equity in a company. The SEC's investor education site explains it directly: a share of stock gives stockholders a share of ownership in a company.⁵

What that ownership represents, in accounting terms, is the residual claim after all creditors are paid. A company has assets (factories, cash, inventory, intellectual property) and liabilities (bonds it issued, loans it owes, accounts payable). What is left when you subtract the liabilities from the assets belongs to the shareholders. That remainder is shareholders' equity, sometimes called stockholders' equity or book value.

Say a small company has $10 million in total assets and $6 million in liabilities. Shareholders' equity is $4 million. If there are 1 million shares outstanding, book value per share is $4. The market price may trade well above or below that figure depending on what investors expect the company to earn in the future, but the underlying equity calculation is the same formula: value minus debt.

When you own 1,000 shares of a company with 1 million total shares outstanding, you own 0.1 percent of the equity. If the company earns more, retains those earnings, and grows its asset base faster than its liabilities, the book value per share rises. That rising equity is part of what drives long-run stock price appreciation.

Equity is not the same as net worth

This is a distinction worth making explicit, because the two ideas often get blurred. Net worth is the total picture: every asset you own minus every liability you carry. Home equity, auto equity, brokerage account balances, retirement savings, cash, the balance on a credit card, the student loan, the car note: all of it nets together into your overall net worth.

Equity is narrower. It is always attached to a specific asset and the specific debt against that asset. The equity in your home says nothing about the credit card balance you carry or the 401(k) you have been building. Those live in the larger net-worth calculation.⁴ The Survey of Consumer Finances, collected by the Federal Reserve every three years, consistently finds that home equity accounts for the largest share of total wealth for households in the middle wealth quintiles, which is why understanding how it builds, and what can erode it, matters more than most people realize.⁶

What this means for your decisions

There is a practical layer to all of this. Equity is not just a number on paper. It is collateral, a potential source of financing, and a measure of progress on the largest purchase most people will ever make. A home equity loan lets you borrow a fixed amount against that accumulated ownership stake.¹ A home equity line of credit, or HELOC (a revolving credit line secured by your home), gives you flexible access against the same stake.² Both instruments use your equity as the security, which is why building it steadily, through consistent mortgage payments and by not over-borrowing against it, is worth the discipline.

Overall, equity is the concept that unifies two of the most important financial arenas in a household's life: real estate and investing. In both places it asks the same question: after everything owed is accounted for, what portion is genuinely yours? The answer to that question, tracked over years, is usually the clearest measure of financial progress available.