BlogTax EstimatorCapital Gains Tax Estimator: Understand Your Investment Tax Bill
Tax Planning6 min readJune 20, 2025

Capital Gains Tax Estimator: Understand Your Investment Tax Bill

Selling stocks, funds, or property triggers capital gains taxes. The rate depends on how long you held the asset and your total income.

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Capital gains tax applies when you sell an asset for more than you paid. Long-term gains (assets held over one year) are taxed at 0%, 15%, or 20% depending on your income. Short-term gains are taxed as ordinary income at your marginal rate, which can be as high as 37%.

The Hidden Tax Bill in Your Investment Account

You're up $20,000 in your brokerage account. But when you sell, the IRS is entitled to a portion of that gain. How much depends on two things: how long you held the asset and your total taxable income.

Selling after 364 days instead of 366 can mean the difference between a 22% rate and a 15% rate on a significant gain.

Americans paid $270 billion in capital gains taxes in fiscal year 2022. Source: Congressional Budget Office (2023) — Source

Short-Term vs. Long-Term: The Critical Distinction

Short-term (held one year or less): taxed as ordinary income — same rate as your wages. Long-term (held more than one year): preferential rates of 0%, 15%, or 20%.

Filing Status0% Rate15% Rate20% Rate
SingleUp to $47,025$47,026–$518,900Over $518,900
Married JointlyUp to $94,050$94,051–$583,750Over $583,750

The 0% long-term capital gains rate applies to taxable income below $47,025 for single filers (2024). Source: IRS Rev. Proc. 2023-34 — Source

Tax-Loss Harvesting

Selling positions with unrealized losses before year-end can offset your gains. The rules:

  • Losses offset gains of the same type first
  • Net losses offset gains of the other type
  • Up to $3,000 of net losses can offset ordinary income per year
  • Watch the wash sale rule: no "substantially identical" security within 30 days before or after

Tax-loss harvesting can add 0.5%–1.5% in after-tax returns annually for taxable accounts. Source: Vanguard (2022) — Source

See the tax estimator guide, tax planning strategies, and Roth conversion calculator.

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Frequently Asked Questions

What is the capital gains tax rate for 2024?
Long-term capital gains rates for 2024: 0% for taxable income up to $47,025 (single) or $94,050 (married jointly); 15% up to $518,900 (single) or $583,750 (jointly); 20% above those thresholds. Short-term gains are taxed at your ordinary income rate.
How do I calculate capital gains?
Capital gain = sale price minus your cost basis (what you paid, including commissions). If you received shares through an employer plan, your cost basis may be the fair market value on the vesting date.
Can I offset capital gains with losses?
Yes. Capital losses offset capital gains dollar-for-dollar. If losses exceed gains, you can deduct up to $3,000 against ordinary income per year, with excess losses carried forward to future years.

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