To calculate capital gains tax, subtract your adjusted cost basis (original purchase price + fees) from the net sale price (selling price - commissions). Gains on assets held ≤ ≤ 1 year are taxed as ordinary income. Long-term gains (> 1 year) are taxed at 0%, 15%, or 20% based on taxable income.
How to Calculate Capital Gains Tax (3 Steps)
Long-Term Capital Gains
On a $100,000 capital gain, you'll likely pay 15% for long-term gains, resulting in about $15,000 in federal tax (plus potential state tax), but it could be 0% or 20% depending on your total taxable income and filing status, while short-term gains are taxed as ordinary income (potentially 22-24%).
Capital gains tax on $300,000 depends on your filing status and total income, but for most, it will be taxed at the 15% federal rate, meaning around $45,000 in tax, potentially rising to 20% if your total income is very high, and you'll also need to account for state taxes and potentially a 3.8% Medicare surtax. A $300,000 gain usually falls into the 15% bracket for single filers (above $48,350) and married filing jointly (above $96,700), while for married filing separately, it hits the 20% bracket (over $300,000).
How to calculate your AGI. Start with your total (gross) income from all sources. This includes wages, tips, interest, dividends, capital gains, business income, retirement income and other forms of taxable income.
The "6-year rule" for Capital Gains Tax (CGT) in Australia allows you to treat a former main residence as tax-exempt for up to six years after you move out, even if you rent it out, enabling you to avoid CGT on any growth during that period. You qualify by moving out, choosing to treat it as your main home for tax, and can reset the rule by moving back in. If you rent it out for longer than six years, only the portion of the gain after the six-year mark becomes taxable.
On a $100,000 capital gain, you'll likely pay 15% for long-term gains, resulting in about $15,000 in federal tax (plus potential state tax), but it could be 0% or 20% depending on your total taxable income and filing status, while short-term gains are taxed as ordinary income (potentially 22-24%).
On the sale (or disposal) of something (an 'asset'), if it has increased in value to the extent that you make a profit, CGT may be due. In simple terms, CGT is a tax on the profit when you dispose of an asset that's increased in value.
To calculate your capital gain or loss, you need to subtract the original cost of the asset and any associated expenses from the selling price. The remaining amount is your capital gain (if positive) or capital loss (if negative).
The "36-month rule" for capital gains tax (CGT) primarily refers to the UK's Principal Private Residence (PPR) Relief, where the final 36 months (or 9 months for most) of a property's ownership period are tax-exempt, even if not lived in, provided it was a main home at some point. In the US, the relevant rule for home sales is the "2-out-of-5-year rule" for the Section 121 exclusion, allowing up to $250k/$500k profit tax-free if owned and used as a main home for 2 of the 5 years before sale, with exceptions for unforeseen circumstances.
While capital gains may be taxed at a different rate, they're still included in your adjusted gross income (AGI) and can affect your tax bracket and your eligibility for some income-based investment opportunities.
On a $100,000 capital gain, you'll likely pay 15% for long-term gains, resulting in about $15,000 in federal tax (plus potential state tax), but it could be 0% or 20% depending on your total taxable income and filing status, while short-term gains are taxed as ordinary income (potentially 22-24%).
To qualify for 0% capital gains tax, you must have long-term capital gains (assets held over a year) and your taxable income (after deductions) must fall below specific IRS thresholds, which change annually but are roughly <$48,350 for single filers and <$96,700 for married filing jointly for the 2025 tax year, allowing for higher total income when combined with deductions like the standard deduction. The key is keeping your adjusted gross income (AGI) low enough so that after subtracting deductions, your taxable income remains within these limits.
If you plan to sell your property after 24 months, the gains will be taxed under the long-term capital gain tax for property. After July 2024, there have been several changes to how property gains are taxed, indexation benefits and exemptions.
The 20% rule for capital gains refers to the highest federal tax rate for long-term capital gains, applying to higher income brackets when you sell investments (stocks, real estate) held for over a year, with lower rates of 0% and 15% for lower incomes, and even higher rates for special assets like collectibles. This rate kicks in for single filers earning over approximately $492,300 (2024) or $533,401 (2025), and higher for joint filers, making holding assets over a year a key tax strategy.
Long-term capital gains can't push you into a higher tax bracket, but short-term capital gains can. Understanding how capital gains work could help you avoid unintended tax consequences. If you're seeing significant growth in your investments, you may want to consult a financial advisor.
On a $100,000 capital gain, you'll likely pay 15% for long-term gains, resulting in about $15,000 in federal tax (plus potential state tax), but it could be 0% or 20% depending on your total taxable income and filing status, while short-term gains are taxed as ordinary income (potentially 22-24%).
To avoid the 22% tax bracket (or any higher bracket), focus on reducing your taxable income through strategies like maxing out 401(k)s and HSAs, deferring bonuses, tax-loss harvesting, smart charitable giving, and strategic asset location, understanding that higher rates only apply to income within that bracket, not your entire income.