Capital Gains Tax Calculator 2026

Two cliffs to watch: 0% LTCG bracket headroom + 3.8% NIIT cliff at $200K/$250K MAGI. Sell now, split across years, or wait. Free.

Instantly calculate capital gains tax on stock sales. Know exactly what you owe before you sell. FREE TIER: • Federal capital gains tax (short-term vs long-term) • NIIT (3.8% Medicare surtax) calculation • Holding period detection (< 1 year vs ≥ 1 year) • Income-based long-term rates (0%, 15%, 20%) • Complete breakdown: federal tax, NIIT, effective rate, net proceeds PRO UPGRADE ($4.99 one-time): • All 50 state capital gains tax rates • Tax-loss harvesting calculator • Cost basis methods (FIFO, LIFO, Specific ID, Average Cost) • Advanced scenario testing HOW IT WORKS: 1. Enter purchase price and sale price 2. Select holding period (short or long-term) 3. Enter other taxable income and filing status 4. Get instant tax calculation LONG-TERM GAINS (held ≥ 1 year): • 0% rate up to $48,350 (single) / $96,700 (married) • 15% rate up to $533,400 (single) / $600,050 (married) • 20% rate above those thresholds SHORT-TERM GAINS (held < 1 year): Taxed as ordinary income at standard federal rates (10% - 37%) NIIT (Net Investment Income Tax): Additional 3.8% Medicare surtax when MAGI exceeds $200K (single) or $250K (married)