QSBSCalc
Interactive decoder

The §1202 engine,
run in your browser.

Add one issuance row per QSBS holding. The decoder applies the right rule set based on issuance date relative to the OBBBA effective date (2025-07-04), computes the tiered or binary exclusion, applies the greater of the statutory cap or 10× basis, and overlays the state-of-residence conformity rule. Multi-issuance portfolios are aggregated below the per-row cards.

Privacy: All inputs and computations stay in your browser. No network request carries your sale-value, basis, dates, or state. Read how the decoder works.

Issuance batch

Add one row per QSBS issuance. The decoder models pre- and post-OBBBA stock together. Inputs stay in your browser — nothing is sent to a server.

Issuance 1 · post-OBBBA
/ $75M ceiling
10× = 1,000,000
negative = loss path
Issuance 1 · post-OBBBA · 5.00y
75% post-OBBBA tier
$3,000,000
federal exclusion
Federal taxable$1,000,000
Federal tax on unexcluded$280,000
State add-back$3,000,000
State tax$532,000
Combined tax$812,000
Effective rate on gain20.3%

Estimate. Reproduces the formula on /methodology to the cent for in-cap scenarios. The 28% rate on unexcluded gain is IRC §1202(a); the over-cap slice is taxed at the baseline LTCG (20%) + NIIT (3.8%) rate. Verify with a CPA / EA before acting on any §1202 decision.

Statute
The statute behind each number

Every output traces to primary source

The decoder is a calculator over the statute. Below: the four rules that most often change the answer, then four supporting references.

Supporting branches

§1045 rollover branch — 60-day window to reinvest into replacement QSBSIRC §1045
§1244 small-business-stock loss alternative — ordinary loss treatmentIRC §1244
Reporting on Form 8949 — adjustment code Q for the §1202 exclusionIRS Form 8949 instructions
Capital-gains framework — IRS Pub 550 walks through the QSBS treatmentIRS Pub 550