Capital Gain

A capital gain is the amount by which the proceeds of selling or exchanging a capital asset exceed the asset's adjusted basis. Three things have to be true before one exists: the property has to be a capital asset, there has to be a sale or exchange, and the amount realized has to be greater than the adjusted basis. Each of those is defined somewhere in the tax code, and the bare phrase "capital gain" is not.

That last point is worth stating plainly rather than treating as a curiosity, because it explains why the subject is harder to look up than it should be. IRC 1222 defines eleven terms, and every one of them is either short-term or long-term or a net combination: short-term capital gain, short-term capital loss, long-term capital gain, long-term capital loss, the four netted forms, capital gain net income, net capital loss and net capital gain. There is no definition of the umbrella. What the Code defines instead is the capital asset, at IRC 1221, and the holding period that sorts a gain into one bucket or the other.

This page covers what a capital gain is and when one comes into existence. How it is then taxed, which involves separate rate schedules, an additional tax on investment income for higher earners and a reset of basis at death, belongs to the page on capital gains tax.

IRC 1221 defines a capital asset backwards, and the direction is the point. The section reads: "the term 'capital asset' means property held by the taxpayer (whether or not connected with his trade or business), but does not include," followed by eight categories. So the statute does not list what counts. It assumes everything counts and then carves out exceptions. The default position is that property you own is a capital asset.

The eight exclusions are overwhelmingly about business activity: stock in trade and inventory; depreciable property and real property used in a trade or business; certain self-created intangibles such as copyrights and literary, musical or artistic compositions, and letters and memoranda, in the hands of the person who created them; accounts and notes receivable acquired in the ordinary course of business; certain United States Government publications received other than by purchase; commodities derivative financial instruments held by dealers; hedging transactions; and supplies regularly used or consumed in the business.

Read that list and notice what is absent from it. Your car is not there. Nor is your furniture, your engagement ring, your boat, or your home. Personal-use property is a capital asset, which surprises people, and it means that selling a personal possession for more than its adjusted basis produces a taxable capital gain in the same way that selling shares does.

Two things usually keep that out of view, and it is worth knowing which one is doing the work in any particular case. Used possessions mostly sell for less than they cost, so there is no gain to report in the first place. And the main home, which is the one item on that list that commonly appreciates, has a separate provision of its own that excludes a substantial amount of the gain from income where the conditions for it are met. That exclusion is a subject in its own right and is not covered here. Where neither applies, as with collectibles, precious metals or a car that turned out to be desirable, the gain is real. The mirror image, and the more consequential half of the asymmetry, is that a loss on the same property is generally not deductible at all, which belongs with capital losses.

Nothing happens until realization, and the Code's own definitions are built on that. A holding whose price has risen produces no gain, no income and no filing obligation. IRC 1222 says so in the structure of its definitions: short-term capital gain means gain from the sale or exchange of a capital asset held for not more than one year "if and to the extent such gain is taken into account in computing gross income," and the long-term definition is worded the same way. Until a gain is taken into account it is not one of the things the section defines. Before that point what you have is an unrealized gain, which is a measurement rather than an event.

The measurement is against adjusted basis, not against what you paid, and the difference is not academic. Basis moves while you own something: it rises for capital improvements and for reinvested distributions, and it falls for depreciation and for returns of capital. Two people who paid the same price for the same asset on the same day can therefore have different gains on sale years later. How basis is established and adjusted is a subject in its own right and is covered on the page for cost basis.

The holding period sorts the gain, and the boundary is exact. IRC 1222 distinguishes property "held for not more than 1 year" from property "held for more than 1 year." Those two phrases exhaust the possibilities and they meet at a point, so an asset sold on the first anniversary of its purchase was held for exactly one year, which is not more than one year, and the gain is short-term. The informal phrasing "sold within a year" gets this wrong at precisely the edge where the distinction has any consequence.

Two statutory terms in the same section sound identical and are not, which is worth knowing before reading any tax material closely. Capital gain net income, at 1222(9), is the excess of gains from sales of capital assets over the losses from such sales. Net capital gain, at 1222(11), is the excess of the net long-term capital gain over the net short-term capital loss. They are different figures computed for different purposes, and net capital gain is the one the rate rules operate on.

You dispose of a capital asset. The amount realized is what you receive, and from it you subtract the adjusted basis of the property. A positive result is a capital gain, a negative one is a capital loss, and the holding period decides which of the statutory categories it falls into. The figure is reported for the year of the sale and takes its place in the netting of your gains and losses before any rate is applied to what survives.

A hypothetical example of the whole calculation. Priya buys 200 shares at $30.00 in March 2024, paying $6,000, plus a $10 commission. Her cost basis is $6,010 ($6,000 + $10), because the costs of purchase are part of basis. She makes no further investment and receives no distributions, so her adjusted basis is unchanged.

In June 2026 she sells all 200 shares at $46.00, realizing $9,200 (200 × $46.00). Her capital gain is $3,190 ($9,200 − $6,010). She held the shares from March 2024 to June 2026, which is more than one year, so under IRC 1222(3) it is a long-term capital gain.

Change one fact to see where the boundary sits. Had she sold on the first anniversary of the purchase rather than after it, the same $3,190 would have been a short-term capital gain under IRC 1222(1), because the statute asks whether the asset was held for more than one year and exactly one year is not more than one year. Nothing about the shares or the profit would have differed. Only the category would.

Pros

• A gain arises only on a disposition, so the timing of the event is generally within the owner's control.
• Measuring against adjusted basis means only actual profit is counted, and costs of purchase and improvements are recognized rather than ignored.
• The definitional structure is broad, so most of what an ordinary person owns falls inside a single, well-established set of rules.
• The holding period distinction is objective and easy to document, which makes the category of a gain rarely disputable.

Cons

• The definition by exclusion means people underestimate its reach, and gains on personal possessions and collectibles are genuinely taxable.
• The asymmetry with losses is severe: a gain on personal-use property counts while a loss on it generally does not.
• Basis for long-held or inherited property is often poorly documented, and a basis that cannot be established produces a larger gain than the real one.
• The one-year boundary is exact and easy to miss by a day, and the informal phrasing of it circulates in a form that is wrong at the edge.