Capital Gains Tax Calculator - 2026 Investment Tax Estimate

Most long-term gains in 2026 use 0% to $49,450 single or $98,900 joint, 15% to $545,500 single or $613,700 joint and 20% above, stacked above ordinary taxable income. The $19,500 example gain at $30,000 ordinary single is $8 at 0% plus a sliver at 15%, while at $75,000 ordinary it is $2,925 entirely at 15% per IRS Rev. Proc. 2025-32.

Basis is purchase price plus eligible acquisition costs and improvements, reduced by depreciation or return of capital, and amount realized is sale price minus selling costs. Gain is $44,500 realized minus $25,000 basis equals $19,500 in the example. Reinvested dividends increase basis and lower the gain, so review brokerage records.

Long-term is cheaper when the gain can use 0% or 15% versus ordinary 22% to 24%. At $75,000 ordinary single, long-term is $2,925 at 15% versus $4,290 short-term at 22%, saving $1,365. At $30,000 ordinary, long-term is $8 versus $2,340 short-term, saving $2,332 because the 0% band is open.

Net Investment Income Tax is 3.8% on the lesser of net investment income or MAGI above $200,000 single or $250,000 joint. On $190,000 ordinary plus $19,500 gain ($209,500 MAGI), NIIT is $361 on $9,500 excess. On $75,000 ordinary plus $19,500 gain, MAGI is well below the threshold and NIIT is $0.

Yes, losses first net against gains: a $5,000 loss with the $19,500 gain nets to $14,500, cutting long-term tax from $2,925 to $2,175 and saving $750 at 15%. Up to $3,000 of excess loss can offset ordinary income yearly, with the remainder carried forward under IRS Publication 550.

At $75,000 ordinary single in the 15% long-term band, an extra $5,000 gain adds $750 in federal tax (15% × $5,000) and zero NIIT, so long-term tax rises from $2,925 to $3,675. At $190,000 ordinary near the NIIT line, the same $5,000 adds $750 plus $190 NIIT on the $5,000 excess, totaling $940.

This calculator does not include: (1) state income tax, which can add 0% to 13.3% depending on state; (2) special rates for collectibles at 28% or unrecaptured section 1250 at 25%; or (3) wash-sale deferrals that disallow a loss when substantially identical securities are repurchased within 30 days. Federal only — state income tax not included.

No, this is an estimate for planning. Filing requires exact cost-basis lots, holding periods, wash-sale adjustments, loss carryforwards, qualified dividends, state apportionment and form validation. The estimate can differ from your return due to lot method, settlement dates or data entry. Use IRS forms or a licensed preparer to file.

At $75,000 ordinary single, a $50,000 long-term gain stacks to $125,000 taxable, using $20,950 of remaining 15% band to $545,500 for $3,143 at 15%, while the 22% ordinary band is unaffected. Short-term on the same $50,000 at 22% marginal would be $11,000, so long-term saves $7,857 on that $50,000.

Yes, each reinvested dividend buys a new tax lot that increases total basis. Missing $2,000 in reinvested dividends on the $25,000 purchase overstates the $19,500 gain to $21,500 and overstates long-term tax by $300 at 15%. Verify brokerage Form 1099-B basis and keep your own lots for transferred holdings.