Equity is the value you actually own in something after subtracting what you owe. Whether you’re talking about a home, a company, or shares of stock, the core idea is the same: equity is your ownership stake, measured in dollars. The concept shows up in several areas of personal finance and business, and understanding each one helps you make smarter decisions about buying a home, negotiating a job offer, or investing.
The Basic Formula
Every form of equity traces back to one simple equation: take what something is worth, subtract what’s owed against it, and the remainder is equity. In accounting terms, a company’s total assets minus its total liabilities equals its shareholders’ equity. On a personal level, the market value of your house minus your remaining mortgage balance equals your home equity. The math is identical whether you’re looking at a corporate balance sheet or your own finances.
How Home Equity Works
Home equity is the portion of your property that you truly own. The formula is straightforward: your home’s current market value minus the principal you still owe on your mortgage. If your home is worth $400,000 and you owe $250,000, you have $150,000 in equity.
You build home equity in two ways. First, every monthly mortgage payment chips away at your loan balance. Early in a mortgage, most of your payment goes toward interest, so equity growth from payments alone starts slowly and accelerates over the life of the loan. Second, your home can appreciate in value. The national average for home appreciation runs about 3% per year, though your local market may vary significantly. If your $400,000 home appreciates 3% in a year, it’s now worth $412,000, and your equity grows by $12,000 on top of whatever principal you paid down.
Home equity matters because it represents real, usable wealth. You can tap it through a home equity loan or line of credit to fund renovations, consolidate debt, or cover large expenses. When you eventually sell, your equity is roughly what you walk away with after paying off the mortgage and closing costs. Renovations, market downturns, and neighborhood changes can all shift your equity up or down, so it’s not a fixed number.
How Business Equity Works
In a business context, equity represents ownership. If you start a company, you own 100% of it. As you bring in partners, investors, or employees who receive shares, ownership gets divided. The total equity of a company is what would be left over if the business sold all its assets and paid off every debt. That leftover value belongs to the shareholders, split according to how many shares each person holds.
For publicly traded companies, equity is easy to see: it’s the stock price multiplied by the number of shares outstanding, known as market capitalization. For private companies like startups, equity is harder to pin down because there’s no public market setting the price. Instead, the company’s value gets established during fundraising rounds when investors agree on a valuation.
How Startup Equity Dilution Works
When a startup raises money, it issues new shares to investors, which reduces every existing shareholder’s percentage of ownership. This is called dilution. Here’s a concrete example: imagine you found a company and own 100% of 1 million shares, with a company valuation of $1 million. You then raise $500,000 from investors at a $2 million pre-money valuation. The company issues 250,000 new shares to those investors, bringing the total to 1.25 million shares. Your ownership drops from 100% to 80%.
But here’s the key: your 80% stake is now worth $2 million, double what your 100% stake was worth before. If the capital raised is used effectively to grow the company, a smaller slice of a much bigger pie can be worth far more. That said, dilution also reduces your voting power and your share of future profits or acquisition proceeds. Early-stage fundraising is the most expensive capital a founder will ever take, because investors receive a larger ownership percentage for each dollar when the company’s valuation is still low.
Dilution typically happens during fundraising rounds, employee stock option grants, and conversion of convertible debt into shares.
How Employee Stock Equity Works
Many companies, especially in tech, offer equity compensation as part of a job package. The two most common forms are restricted stock units (RSUs) and stock options.
RSUs are a promise that the company will give you actual shares of stock once you meet certain conditions, usually staying at the company for a set period. You don’t pay anything to receive them. Once they vest (meaning the waiting period is over and the shares become yours), their value equals the current market price of the stock. If your company’s stock is trading at $150 and 100 RSUs vest, you receive $15,000 worth of stock. RSUs always have some value as long as the stock price is above zero.
Stock options give you the right to buy shares at a predetermined price, called the strike price. If the company’s stock rises above that price, the difference is your profit. For example, if your strike price is $20 and the stock is trading at $50, each option is worth $30. But if the stock stays at or below $20, the options are worthless because you’d be paying the same as or more than the market price. This makes options riskier than RSUs but potentially more rewarding if the stock price climbs significantly.
Both RSUs and stock options typically vest over a multi-year schedule, often four years. A common structure is a one-year “cliff” where nothing vests for the first 12 months, followed by monthly or quarterly vesting for the remaining three years. This gives the company a retention tool and gives you a growing ownership stake as long as you stay.
Taxes on Equity Gains
When you sell an asset for more than you paid, the profit is a capital gain, and it’s taxable. How much you owe depends largely on how long you held the asset.
If you held the asset for more than one year before selling, the gain is considered long-term and taxed at preferential rates. For 2026, long-term capital gains rates are 0%, 15%, or 20%, depending on your taxable income. A single filer pays 0% on gains up to $49,450, 15% on gains above that threshold, and 20% only when taxable income exceeds $545,500. Married couples filing jointly hit the 15% bracket at $98,900 and the 20% bracket at $613,700.
Short-term capital gains, from assets held one year or less, are taxed as ordinary income at your regular tax rate, which can be significantly higher.
RSUs are taxed differently at the point of vesting: the market value of the shares on the day they vest counts as ordinary income. If you hold those shares after vesting and sell them later at a higher price, the additional gain is taxed as a capital gain, with the long-term or short-term rate depending on how long you held the shares after vesting.
Home equity gets a special tax break. When you sell your primary residence, you can exclude up to $250,000 in gains from taxes as a single filer, or $500,000 as a married couple filing jointly, as long as you’ve lived in the home for at least two of the past five years.
How Equity Grows Over Time
Regardless of the type, equity tends to build through a combination of paying down debt and appreciation. A homeowner who makes regular mortgage payments while the housing market rises builds equity from both directions simultaneously. An employee whose RSUs vest while the company’s stock price climbs benefits from both the vesting schedule and market growth. A business owner who reinvests profits into growing the company increases the value of their ownership stake.
The flip side is that equity can shrink. A housing market downturn can wipe out home equity, potentially leaving you “underwater,” meaning you owe more than the home is worth. A company’s stock price can fall, reducing the value of your shares. A startup that fails can make equity worthless entirely. Equity always carries some element of risk because its value is tied to the market price of the underlying asset, which can move in either direction.