How Capital Gains Are Taxed

What counts as a capital asset

The IRS starts from a wide default: almost everything you own and use for personal or investment purposes is a capital asset. That includes a home, personal-use items such as household furnishings, and stocks or bonds held as investments.

When you sell one, the difference between your adjusted basis and the amount you realized is a capital gain or a capital loss. You have a gain if you sell for more than adjusted basis and a loss if you sell for less.

One asymmetry deserves emphasis because it costs people money every year: losses from the sale of personal-use property, such as your home or car, are not deductible. The gain side is still taxable, subject to any exclusion that applies. Selling a car for more than you paid is a reportable gain; selling it for less, which is what almost always happens, produces nothing at all. The same logic applies to a personal residence, where gains above the §121 exclusion are taxable but a loss is simply lost.

The main categories that are not capital assets are inventory and property held primarily for sale to customers, depreciable business property and real property used in a trade or business, which fall under §1231 and Form 4797 instead, and self-created works in the hands of their creator. Business property has its own regime, which is why a rental sale generates §1250 recapture rather than a straightforward capital gain.

The holding period, counted exactly

Classification comes first, because it decides which rate schedule applies. Hold the asset for more than one year before disposing of it and the gain or loss is long-term. Hold it one year or less and it is short-term.

The counting rule is precise and worth committing to memory: count from the day after the day you acquired the asset, up to and including the day you disposed of it.

Work through it. You buy shares on 10 March 2025. The holding period begins 11 March 2025. On 10 March 2026 you have held the asset for exactly one year, which is not more than one year, so a sale that day is short-term. Sell on 11 March 2026 and the gain is long-term.

That single day can be worth a great deal. A short-term gain is taxed as ordinary income at graduated rates reaching 37 percent, while the same gain held one day longer may be taxed at 15 percent or even 0 percent. Selling a day early is among the most expensive avoidable mistakes an investor can make, and it happens constantly in December when people sell for tax reasons without checking the acquisition date.

Exceptions exist for property acquired by gift, property acquired from a decedent, patent property, commodity futures, and applicable partnership interests. The first two are common enough to cover separately below.

Determining your basis

Basis is generally what the asset cost you, but the number that matters at sale is adjusted basis, and most people understate it. Every dollar of basis you can substantiate is a dollar of gain you never report.

Things that increase basis:

• Purchase price plus commissions, transfer taxes, and acquisition fees.
• Capital improvements to real property. A new roof or an addition adds to basis; routine repairs and maintenance do not.
• Reinvested dividends and capital gain distributions. Each reinvestment is a purchase of additional shares at that price. Investors who forget this and report the original investment as their entire basis pay tax twice on the same money.
• Assessments for local improvements and certain legal fees.

Things that decrease basis:

• Depreciation allowed or allowable, which is why rental property tends to carry a much lower basis than its owner expects.
• Casualty losses deducted, insurance reimbursements, and return-of-capital distributions.
• Deferred gain rolled in from a like-kind exchange. Our 1031 Exchange guide explains how that carryover basis is computed.

Which shares did you sell?

When you hold multiple lots of the same security bought at different prices, the lot you are treated as selling changes the gain. The default is first in, first out, which sells your oldest and often lowest-basis shares first and tends to maximise the reported gain. The alternative is specific identification, where you tell the broker at or before the sale exactly which lot to sell.

Specific identification is the single most under-used tool in retail investing. It lets you choose high-basis lots to reduce a gain, or deliberately select long-term lots to avoid short-term treatment. It generally has to be done at the time of the trade, not reconstructed afterwards, and the instruction must be confirmed by the broker. Mutual funds also permit average-cost methods with their own election rules.

Inherited and gifted property

These two follow opposite rules, and confusing them is expensive.

Inherited property. Property acquired from a decedent generally takes a basis adjusted to its value at the date of death under IRC §1014. Unrealized appreciation accumulated during the decedent's lifetime is wiped out. A gain is also treated as long-term regardless of how long the heir actually held it.

Gifted property. A gift generally carries the donor's basis across to you under IRC §1015, and the donor's holding period tacks onto yours. The built-in gain travels with the asset.

The planning implication is direct and frequently missed. Giving a highly appreciated asset to a family member during your lifetime transfers the embedded tax liability to them. Leaving the same asset in your estate may eliminate that liability entirely through the basis adjustment. When the intended recipient is in a lower bracket the gift can still be the better answer, but it should be a decision rather than an accident.

A special rule applies where gifted property has declined in value: a dual basis applies, using the donor's basis to figure a gain and the lower fair market value at the date of gift to figure a loss, which can produce neither gain nor loss in between. Publication 551 covers the mechanics.

The netting rules

Gains and losses do not go into one pot. They net in a defined order, and the order determines what a given loss is actually worth to you.

1. Within each category first. Short-term gains net against short-term losses. Long-term gains net against long-term losses. Carryforwards from earlier years join their own category.
2. Then across categories. If one category produces a net loss and the other a net gain, the loss offsets that gain.

The statutory definitions follow from this. Net capital gain, the figure eligible for the preferential rates, means the amount by which your net long-term capital gain exceeds your net short-term capital loss for the year. Net long-term capital gain means long-term gains reduced by long-term losses, including any unused long-term loss carried over. Net short-term capital loss means the excess of short-term losses, including carryovers, over short-term gains.

The $3,000 limit and carryforwards

If your capital losses exceed your capital gains, the excess you can deduct against other income is limited. You may claim the lesser of $3,000, or $1,500 if married filing separately, or your total net loss shown on line 16 of Schedule D. The deduction goes on line 7a of Form 1040, 1040-SR, or 1040-NR.

Anything beyond that is not forfeited. It carries forward to later years, and there is no expiry. The Capital Loss Carryover Worksheet in Publication 550 or in the Schedule D instructions computes the amount you carry.

Two practical consequences follow.

First, the carryforward retains its character. A long-term loss carried into next year is still a long-term loss and nets against long-term gains first. That matters if you expect a large gain of a particular type.

Second, a large loss can take a very long time to use at $3,000 a year. A $60,000 net capital loss with no future gains against it represents twenty years of deductions. Anyone sitting on a substantial carryforward should treat it as a stored asset and plan realisations to use it, for instance by harvesting gains in a year when the carryforward can absorb them. That is the mirror image of loss harvesting and is often the more valuable move.

Note that the $3,000 figure is not indexed for inflation and has not changed in decades, so its real value erodes every year.

The Capital Loss Carryover Calculator takes your short-term and long-term figures and returns this year's deduction alongside the amount carried forward, split by character.

Tax-loss harvesting and the wash sale rule

Harvesting means deliberately realising a loss to offset gains or to create a carryforward, while keeping your overall market exposure roughly intact. The constraint is IRC §1091.

A loss is disallowed if you acquire substantially identical stock or securities within 30 days before or 30 days after the sale. That is a 61-day window centred on the sale date. The most common error is treating it as a forward-looking 30-day rule and buying back on day 31 while forgetting a purchase made three weeks before the sale, including an automatic reinvestment or a recurring contribution.

Three further points:

• The loss is deferred, not destroyed. A disallowed loss is added to the basis of the replacement shares and the holding period tacks, so you recover the benefit when you finally sell the replacement.
• It reaches your other accounts. Buying the same security in an IRA triggers the rule, and in that case the loss is permanently lost rather than added to basis. The IRS position also treats a purchase by your spouse as yours.
• "Substantially identical" is narrower than "similar." Two different index funds tracking different indices are generally not substantially identical, which is what makes harvesting practical, but selling a fund and buying the same fund in a different share class is not a safe distinction.

Our Wash Sale Loss Calculator tests a specific pair of trades against the window, and the Wash Sale Rule guide covers the substantially-identical question in more depth.

Treatment by asset class

Real estate is the class where the surprises concentrate, because depreciation quietly reduces basis every year and converts part of the eventual gain into 25 percent recapture. The Rental Income Tax Calculator and the 1031 Exchange guide deal with that interaction directly. For small business stock, the QSBS Gain Exclusion Calculator sizes the excluded portion.

Which rate applies

Once the gain is classified and netted, the rate follows. Net short-term capital gains receive no preference and are taxed as ordinary income at graduated rates. Net capital gain is taxed at 0, 15, or 20 percent depending on your total taxable income, with three exceptions taxed higher: collectibles at a maximum 28 percent, the taxable part of §1202 stock at a maximum 28 percent, and unrecaptured §1250 gain at a maximum 25 percent.

Higher earners may also owe the 3.8 percent net investment income tax under IRC §1411 once modified AGI exceeds $200,000 single or head of household, $250,000 married filing jointly, or $125,000 married filing separately, which lifts the effective top rate on long-term gains to 23.8 percent.

The rate itself is not the interesting part, because it depends on how the gain stacks on top of your ordinary income rather than on the gain alone. That stacking mechanism, the line-by-line worksheet the IRS uses to apply it, and what makes a dividend qualified are covered in full in our Qualified Dividends and Capital Gains Worksheet guide. If you would rather skip the worksheet, the Capital Gains Rate Calculator applies it for you.

Form 8949 and Schedule D

Most sales and other capital transactions are reported on Form 8949, Sales and Other Dispositions of Capital Assets, where each disposal is listed with its dates, proceeds, and basis. The totals are then summarised on Schedule D (Form 1040). If Schedule D does not apply to you, check the appropriate box on line 7b of Form 1040.

Two operational points cause most of the filing friction.

Basis reporting is not always complete. Brokers report basis to the IRS for covered securities, but for older holdings, transferred accounts, gifts, and inherited assets the basis box may be blank or wrong. Form 8949 has adjustment codes for exactly this situation. A blank basis is not a licence to guess, and it is also not a reason to report zero basis and overpay, which is what happens by default if you accept a broker figure uncritically.

A large gain can trigger estimated tax. Nothing is withheld on a securities sale. If you have a substantial taxable gain you may be required to make estimated tax payments to avoid an underpayment penalty, and Publication 505 sets out the safe harbours. The Quarterly Estimated Tax Calculator can size the payment and the Underpayment Penalty Calculator the exposure if you have already missed a quarter.

Common mistakes

• Selling one day too early. More than one year means more than. Check the acquisition date before any December sale.
• Omitting reinvested dividends from basis. Years of automatic reinvestment are purchases. Leaving them out means paying tax on your own money a second time.
• Accepting a blank or wrong broker basis. Use the Form 8949 adjustment codes rather than defaulting to zero basis.
• Triggering a wash sale on the buy side. The window opens 30 days before the sale, and automatic reinvestments count.
• Harvesting a short-term loss into a long-term-gain year. Character matters; the loss is worth far more against ordinary-rate income.
• Forgetting the carryforward exists. Losses from an earlier year are frequently left unused because nobody carried the schedule forward.
• Expecting a deduction for a personal-use loss. The car and the house do not produce deductible losses.
• Assuming every long-term gain gets 15 percent. Collectibles, §1202 stock, and depreciated real property have higher maximum rates.
• Ignoring estimated tax after a large sale. No withholding happens automatically on a brokerage gain.