Capital Gains Tax Calculator

Tax Year 2025

Capital Gains Tax Calculator

Calculate your tax liability on investment gains and property sales.

  • Calculate both short-term and long-term capital gains taxes
  • Account for capital losses and carry-forwards
  • Determine net investment income tax (NIIT) liability
  • Special calculations for collectibles and qualified small business stock

Capital Gains Tax Basics

Capital gains tax is owed on the profit from selling investments. The tax rate depends on how long you held the asset and your total income level.

2025 Tax Rates

  • Short-term (≤1 year): Taxed as ordinary income (10%-37%)
  • Long-term (>1 year): 0%, 15%, or 20% based on income
  • NIIT: Additional 3.8% for high earners
  • State taxes: Varies by state (0%-13.3%)

Holding Period Rules

Assets held for more than one year qualify for long-term capital gains treatment with preferential tax rates. The holding period starts the day after purchase and includes the sale date.

Cost Basis Calculation

  • • Original purchase price
  • • Plus: Broker commissions and fees
  • • Plus: Capital improvements (real estate)
  • • Plus: Selling expenses
  • • Minus: Depreciation taken (if applicable)

Tax Planning Tips

  • • Hold assets over 1 year for better rates
  • • Harvest losses to offset gains
  • • Consider timing of sales
  • • Use tax-advantaged accounts when possible
  • • Consult a tax professional for complex situations