Capital Gains Tax Calculator — Short & Long-Term

How long you hold an investment before selling changes its tax rate dramatically. Short-term gains (held a year or less) are taxed as ordinary income at rates up to 37%; long-term gains get preferential 0/15/20% federal rates, stacked on top of your other income. High earners may also owe the 3.8% Net Investment Income Tax on top. This calculator models all of it, plus an optional state estimate.

How to Use Capital Gains Tax Calculator

• 1.

  Enter your other annual income and the capital gain amount

• 2.

  Choose short-term or long-term holding period

• 3.

  Select your filing status and, optionally, your state

• 4.

  View the federal tax, NIIT, state tax, and net proceeds after tax

Key Features

• Correct bracket-stacking for both ordinary and long-term capital gains rates
• NIIT (3.8%) applied above the right MAGI threshold
• Optional state estimate that reuses each state's real income tax brackets
• Net proceeds and effective rate shown alongside the tax breakdown

When to Use This Tool

• •

  Deciding whether to hold an investment a few more weeks to reach long-term treatment

• •

  Estimating the tax hit before selling stock, crypto, or a rental property

• •

  Checking whether a large gain will push you into NIIT territory

• •

  Comparing after-tax proceeds across different states before relocating

Frequently Asked Questions