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QSBS §1202 capital-gains exclusion calculator.

Free QSBS §1202 calculator for founders and early employees. Inputs original cost basis, holding period, exit value, and corporate eligibility. Outputs federal exclusion amount (up to $10M or 10× basis), §1045 partial-rollover scenarios, and state-level addbacks.

Educational only · not investment, tax, or legal advice · confirm with your CPA

The calculator.

All inputs are local — nothing is sent to a server. Calculations run client-side in your browser.

What you paid for the QSBS originally
What you sold (or plan to sell) the QSBS for
Need 5+ years for full §1202 exclusion (post-2010 stock)
CA = 13.3 (no §1202 conformity), TX/FL/WA = 0, NY = 10.9
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Estimates assume post-2010 QSBS for 100% exclusion · educational only
Total capital gain
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§1202 cap (greater of $10M or 10× basis)
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Federal excluded
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Federal tax (after exclusion)
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State tax (no §1202 conformity)
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Total tax savings
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Common questions about this calculator.

How does the §1202 exclusion work?
Up to $10M (or 10× the original basis, whichever is greater) of capital gains on Qualified Small Business Stock can be excluded from federal capital gains tax. Six conditions: C-corp, gross assets ≤ $50M when issued, qualified trade or business, original-issuance acquisition, 5-year holding period, post-2010 holding for full exclusion.
What is the holding period requirement?
Five years from the date you acquired the stock. Shorter holds disqualify. If you exercise options into QSBS-qualifying stock, the holding period starts on the exercise date, not the option grant date.
What is §1045 rollover?
If you sell QSBS held for more than 6 months but less than 5 years, you can roll the proceeds into NEW QSBS within 60 days and defer recognition. The new QSBS continues toward the 5-year clock.
Do all states honor §1202?
No. California does NOT conform to §1202 — California taxes QSBS gain at full state rates (up to 13.3%). Some states partially conform; some fully conform. Check your state-specific addback rules; HELM's State Tax Brain handles this automatically.

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