Short-Term vs Long-Term Capital Gains Tax on Stocks

Maya's Capital Gains Decision: Why Waiting One More Day Can Cut Your Tax Bill

It's a Tuesday night in December, and Maya is staring at her brokerage app. The shares she bought in March for $10,000 are now worth $14,000. That's a $4,000 profit, and she's tempted to sell before the market changes its mind.

Before she taps the button, she has one question about capital gains tax: how much of that $4,000 does she actually keep? The answer depends on a date. If she sells now, she owes one rate. If she waits until mid-March, she owes a lower one.

Maya is an illustrative example. Say she's a 34-year-old physical therapist, single, earning $78,000 a year in salary. She bought the shares on March 14 with money from her savings. Let's follow her through the decision, step by step.

The one-year line that decides your rate

The tax code sorts every stock sale into one of two buckets based on how long you owned the shares.

Hold for one year or less, and your profit is a short-term capital gain. Hold for more than one year, and it's a long-term capital gain. According to the IRS's page on capital gains and losses, your holding period generally starts the day after you buy and includes the day you sell.

That "more than one year" wording trips people up. Exactly one year isn't enough. For Maya, who bought on March 14, selling on March 14 of next year still counts as short-term. Her first long-term day is March 15.

Right now, in December, she's about nine months in. Any sale today lands in the short-term bucket.

A quick note on what's being taxed. Only the gain counts, not the full sale price. Maya's gain is her sale proceeds minus what she paid (her "cost basis"): $14,000 − $10,000 = $4,000. If she reinvested dividends along the way, those reinvested amounts add to her basis, which shrinks her taxable gain.

Short-term gains: taxed like your paycheck

Short-term gains get no special treatment. They're added to your wages and taxed at your ordinary federal income tax rate, the same rate that applies to your salary.

So the first thing Maya needs is her taxable income. She starts with her $78,000 salary and subtracts the standard deduction. For 2025, the IRS standard deduction for a single filer is roughly $15,000 (a mid-year law change nudged it slightly higher, so check the IRS page for the exact figure).

$78,000 − $15,000 = about $63,000 of taxable income.

Next, she checks the IRS federal income tax brackets. For 2025, a single filer's 22% bracket runs from about $48,475 to about $103,350 of taxable income. Maya's $63,000 sits squarely in the middle of it.

Adding a $4,000 short-term gain brings her to $67,000, still well inside the 22% bracket. So the whole gain is taxed at 22%:

$4,000 × 22% = $880 in federal tax.

She'd keep $4,000 − $880 = $3,120 of her profit, before any state tax.

If her gain had been large enough to push her into the 24% bracket, only the portion above the bracket line would be taxed at 24%. Brackets work in layers. Crossing a line never makes your whole income taxed at the higher rate.

Long-term gains: the 0%, 15% and 20% tiers

Long-term gains get their own, much friendlier rate schedule. There are three tiers: 0%, 15% and 20%.

For the 2025 tax year, a single filer pays roughly:

• 0% on long-term gains that fall within taxable income up to about $48,350
• 15% on gains that fall between about $48,350 and $533,400
• 20% on gains above about $533,400

These thresholds adjust for inflation every year, so treat them as 2025 figures.

Here's the part most people miss: your long-term gains stack on top of your ordinary income. Your salary fills up the brackets first, and your gains sit above it. Where the gains land determines their rate.

Maya's ordinary taxable income is about $63,000. That already clears the roughly $48,350 ceiling for the 0% tier. So when her $4,000 long-term gain is stacked on top, all of it falls in the 15% zone:

$4,000 × 15% = $600 in federal tax.

Compare that to the short-term bill: $880 − $600 = $280 saved just by waiting until March 15.

Now consider a different version of Maya to see the 0% tier in action. Say she earned $55,000 instead. Her taxable income would be about $55,000 − $15,000 = $40,000. The 0% tier has about $48,350 − $40,000 = $8,350 of room left. Her entire $4,000 long-term gain fits inside it. Federal tax on the gain: $0.

That's why the long-term rules matter so much for middle-income investors. The same $4,000 gain could cost $880, $600 or nothing, depending on timing and income.

Two more pieces round out the picture. High earners can also owe the 3.8% net investment income tax, which kicks in for single filers with modified adjusted gross income above $200,000. Maya is nowhere near that. And most states tax capital gains as regular income, with no long-term discount, so her state bill (if she lives in a state with income tax) likely won't change based on timing.

Is waiting worth the risk?

$280 is real money. But Maya has to hold the stock for about three more months to get it, and stocks move.

Here's the simple way to think about it. Her tax savings is $280 on a position worth $14,000:

$280 ÷ $14,000 = 2%.

If the shares drop by more than about 2% between now and March 15, the decline wipes out the tax benefit. A 10% drop, which is an ordinary wobble for a single stock, would cost her $14,000 × 10% = $1,400. That's five times the tax savings.

Of course, the shares could also keep rising. Nobody knows. The point is that the tax break isn't free. It's a trade: a guaranteed 2% savings in exchange for three more months of market exposure.

A few situations tilt the decision. If Maya needs the cash in January for a deposit on an apartment, the short-term sale is probably the right call, and $880 is the price of certainty. If the money is long-term savings she won't touch for years, waiting costs her nothing extra, because she'd be holding the shares anyway.

Maya decides the money isn't earmarked for anything soon. She believes in the company's long-run prospects as much as she did in March. She'll wait.

Using a loss to shrink the bill

While she's in the app, Maya notices something else. A different stock she bought in June is down. She paid $5,000, and it's now worth $3,500. That's a $1,500 unrealized loss.

Losses are useful at tax time. The IRS rules let capital losses offset capital gains. If your losses exceed your gains, you can deduct up to $3,000 of the excess against ordinary income each year ($1,500 if married filing separately), and carry any leftover forward to future years.

Maya has two ways to use this loss, and the timing matters.

Option A: Sell both in the same year. If she waits until March to sell the winner and also sells the loser next year, the $1,500 short-term loss offsets her $4,000 long-term gain:

$4,000 − $1,500 = $2,500 net long-term gain
$2,500 × 15% = $375 in tax.

Option B: Sell the loser now, the winner next year. If she sells the losing stock this December, she has a $1,500 loss and no gains this year. The full $1,500 comes off her ordinary income, which is taxed at 22%:

$1,500 × 22% = $330 in tax saved this year.

Then in March she sells the winner and pays $600 on the long-term gain next year. Her net tax across both years: $600 − $330 = $270.

Option B beats Option A by $375 − $270 = $105. The reason: in Option A, the loss cancels out income that would have been taxed at 15%. In Option B, it cancels out income taxed at 22%. A loss is worth more when it offsets a higher rate.

One rule to watch. If Maya sells the losing stock and buys the same stock (or one that's substantially identical) within 30 days before or after the sale, the wash sale rule disallows the loss for now. If she still wants exposure to that company, she has to wait out the 31 days. Or she can move the money into something genuinely different.

Maya sells the loser on December 12. She puts the $3,500 into her savings account and decides not to rebuy.

Maya, 12 months later

Fast-forward to the following December. Here's how her year played out.

December (year one): She sold the losing stock for a $1,500 short-term loss. When she filed her taxes that spring, the loss lowered her taxable income from about $63,000 to about $61,500. At 22%, that cut her federal bill by $330.

March 15 (year two): Her winning shares passed the one-year mark. In our illustration, they'd drifted to $14,300 by then, so her gain grew to $14,300 − $10,000 = $4,300. She sold. As a long-term gain stacked on her salary, it was taxed at 15%:

$4,300 × 15% = $645.

The shares could just as easily have fallen in those three months. Maya accepted that risk, and this time it went her way.

Summer (year two): Knowing she'd owe $645 more than her paycheck withholding would cover, she used the IRS Tax Withholding Estimator to check her W-4. She bumped her withholding up slightly for the rest of the year so she wouldn't face a surprise bill in April.

The scorecard. Compare her path to what would have happened if she'd sold everything in that first December:

Sell everything in December: $4,000 short-term gain − $1,500 short-term loss = $2,500 net short-term gain, × 22% = $550 in tax. Profit kept: $2,500 − $550 = $1,950.

What Maya actually did: Combined gain and loss of $4,300 − $1,500 = $2,800 net. Tax of $645 − $330 = $315. Profit kept: $2,800 − $315 = $2,485.

Some of that difference came from the shares rising, which was luck. But the tax side alone tells the story: she paid an effective rate of $315 ÷ $2,800 = about 11% on her net gains, instead of 22%. She did it by watching one date on the calendar and choosing which year to take her loss.

Nothing about this required a tax professional or a complicated strategy. It required knowing that the clock starts the day after you buy, and that the IRS treats one year and one day very differently from one year flat.

FAQ

Do I owe capital gains tax if I don't sell?

No. Gains are only taxed when you sell (or "realize") them. If Maya's shares go from $10,000 to $14,000 and she keeps holding, she owes nothing on that increase yet. Dividends are different: they're generally taxable in the year you receive them, even if you reinvest them.

Do these rules apply to stocks in my 401(k) or IRA?

Not in the same way. Buying and selling inside a traditional 401(k) or IRA doesn't trigger capital gains tax at all. Instead, withdrawals from traditional accounts are taxed as ordinary income later, and qualified withdrawals from Roth accounts are tax-free. The short-term versus long-term distinction mainly matters in a regular taxable brokerage account.

What if I bought the same stock at different times?

Each purchase is its own "lot," with its own date and cost basis. If you bought shares in March and more in October, selling in April could mean the March shares are long-term and the October shares are short-term. Most brokerages let you choose which lots to sell. Picking the older lots, or the ones with the highest cost basis, can lower your tax bill.

This article is for educational purposes only and is not personalized financial advice.