Capital Gains Tax Calculator — Short-Term vs Long-Term (US)
How long you held an investment changes its tax rate dramatically. Short-term gains (held ≤1 year) are taxed as ordinary income at your regular tax bracket. Long-term gains (held >1 year) get preferential rates — 0%, 15% or 20% federal, depending on your taxable income. Enter your numbers to see the estimated tax on your gain.
US federal estimate using approximate 2025-range bracket thresholds, adjusted annually for inflation — a simplified planning estimate, not tax advice. Excludes state tax, NIIT, and special asset rules (e.g. collectibles, QSBS).
How to use this tool
- Choose short-term (held 1 year or less) or long-term (held over 1 year) — the tax treatment is very different.
- Enter the capital gain amount and your other taxable income for the year (the gain stacks on top of it).
- Pick your filing status.
- Press Calculate to see the estimated federal tax, effective rate, and net proceeds after tax.
Frequently asked questions
What's the difference between short-term and long-term capital gains?
Hold an asset 1 year or less before selling and the gain is short-term, taxed as ordinary income at your regular bracket (up to 37%). Hold it over 1 year and it's long-term, taxed at the lower 0%, 15%, or 20% federal rates — a powerful incentive to hold a bit longer if you're near the 1-year mark.
At what income do I pay 0% long-term capital gains?
For 2025-range figures used here, single filers with total taxable income (including the gain) under roughly $48,350, or married filing jointly under about $96,700, pay 0% federal long-term capital gains tax. Above those thresholds, the rate steps up to 15%, then 20% at the highest income levels.
Does this include state taxes or the Net Investment Income Tax (NIIT)?
No — this estimates federal tax only. Many states also tax capital gains (some at ordinary income rates), and a 3.8% Net Investment Income Tax applies on top for higher earners (over $200,000 single / $250,000 MFJ). Your real total rate can be several points higher than shown here.
Can I offset gains with investment losses?
Yes — capital losses offset capital gains dollar-for-dollar, and up to $3,000 of net losses can offset ordinary income per year, with any excess carried forward to future years. This is called tax-loss harvesting and can meaningfully reduce what this calculator shows.