OpenAI PPU & share sale tax calculator
Three different tax events hide inside "I sold some OpenAI equity": income that settles through payroll (withholding applies, badly), a direct sale of units or shares held a year or less (ordinary rates, nothing withheld), and a long-term sale (capital-gains rates plus NIIT). Pick the event, use your numbers.
Run your event
Which event is yours?
- Settlement via employer: value hitting your W-2 as ordinary income (an RSU-style settlement processed through payroll). Withholding runs at the 22% supplemental rate up to $1M, 37% above — usually far below the real marginal rate.1
- Direct sale, held ≤ 1 year: tender or secondary proceeds where your gain (proceeds − basis) has a short holding period — taxed at ordinary rates plus NIIT, with no withholding at all. The estimated payment for that quarter is entirely on you.
- Direct sale, held > 1 year: long-term rates — 0/15/20% stacked on top of your ordinary income (the 20% line starts at $545,500 single / $613,700 MFJ in 2026), plus 3.8% NIIT.1,2 The PPU→PBC conversion reportedly preserved basis and holding periods, so pre-conversion holding counts — verify yours.
Not sure which applies, or whether your 83(b) history changes your basis? That's exactly the question set covered in the OpenAI employee equity guide and the tender-offer page.
Method and assumptions
- 2026 brackets and LTCG thresholds per IRS Rev. Proc. 2025-32; supplemental withholding per IRS Pub. 15-T; NIIT applied to the full modeled gain when total income exceeds $200K single / $250K MFJ (a simplification of the MAGI test).1,2
- Ignores deductions, credits, AMT, and state bracket structures (flat rate applied; California's top rate is 13.3% and applies equally to gains3). Basis and holding-period questions from the PPU conversion are grant-specific.4 Estimates only — confirm with a CPA.
Know the bill. Then build the plan.
Get matched with a fee-only fiduciary who works OpenAI-scale equity events — conversion basis questions, tender sizing, estimated taxes, multi-year bracket planning. Free, no obligation.
Sources
- IRS Rev. Proc. 2025-32 — 2026 ordinary brackets and LTCG thresholds; withholding per IRS Publication 15-T.
- IRS — Net Investment Income Tax — 3.8% NIIT thresholds and scope.
- California FTB — Capital gains — ordinary-income treatment of gains.
- IRC § 83 and IRS Publication 525 — restricted-property taxation; conversion/basis context per levels.fyi's PPU explainer.
Values verified as of August 2026 for tax year 2026. Educational estimates only — not tax advice.