Block-only Simple mode. Compare selling a block in a secondary versus holding that block to exit, after tax.
Block-only, website-friendly
After-tax comparison
QSBS timing and cap logic
Step 1: Enter your two required numbers
This turns the model on. Step 2 is where founders typically find the biggest dollars, basis, state, and QSBS timing.
If you select "Not sure," results will show both "QSBS qualifies" and "Not QSBS" outcomes for the hold path.
Required to turn the model on.
Next: Add optional details to improve accuracy (basis, dates, state, reinvestment). Most founders find optimization dollars in Step 2.
Step 2 (optional): Improve accuracy
These inputs do not change the required workflow, but they make the output more realistic.
If there was an LLC to C-corp conversion, option exercise timing, or other basis events, confirm with your CPA.
I know my dates (optional)
Dates improve QSBS timing and short-term checks. If you skip dates, the tool still works.
Shown only when QSBS is set to "Yes" or "Not sure".
Add acquisition, secondary, and exit dates to see approximate holding periods.
Show QSBS details
QSBS status at secondary will appear here once dates are entered.
QSBS status at exit will appear here once dates are entered.
Used only for implied IRR. It does not affect QSBS treatment or tax rates.
This does not change calculations. It only tailors the narrative.
Turn on to grow after-tax proceeds instead of assuming cash.
Current assumption: 7.0% per year (net of fees, before interim taxes).
Stores calculator inputs in this browser only (does not store your email).
Quick settings
Simple state presets. No detailed tax customization in this version.
This is a rough proxy and does not model state residency audit risk.
Secondary vs hold snapshot (block-only, base case)
Base case uses your "Base case exit value" (Step 1).
Status: Add inputs
●Block value you may sell
●Base case exit value
●Acquisition, secondary, exit dates
●Years until exit (IRR)
To see results, enter both (1) block value today and (2) base case exit value for that block.
Result
$0
Scroll down to see your results ▼
Enter two numbers to get your snapshot
On the left, enter (1) your block value today and (2) your base case exit value for that same block. Everything else is optional.
Assumptions used in this snapshot
Federal long-term capital gains tax assumed at 20% plus 3.8% NIIT on taxable gain.
If sale appears within 1 year of acquisition, tool treats it as short-term at 37% plus 3.8% NIIT, with no QSBS exclusion modeled.
QSBS cap modeled as a single per-issuer cap for a single taxpayer profile: greater of statutory cap ($10M legacy, $15M post-OBBBA) or 10x basis.
State tax is modeled only via the simple preset and rate input. No residency audit risk modeling.
No QSBS stacking, multi-taxpayer structuring, or detailed QSBS vs non-QSBS tranching.
Areas to optimize and find money
QSBS eligibility confirmation and QSBS vs non-QSBS tranching
Basis nuances (conversions, option exercise timing, QSBS basis vs sale basis)
State residency timing and audit risk
Tender offers vs structured secondary liquidity alternatives (including non-recourse options)
Trust and entity structuring (including stacking) to expand exclusion capacity
Downside protection vs upside preservation tradeoffs beyond a single base case
If you are a venture-backed founder considering a tender offer or secondary sale, and you expect your total personal exit value (combined) to exceed $20 million, we can help you pressure-test the decision with more advanced modeling, validate QSBS and basis, and evaluate structured liquidity alternatives that preserve upside.
Opens a message you can paste into our form, including inputs and assumptions.
Nothing is stored. This runs in your browser unless you choose to share the message with us.
Scenario A: Sell this block in a secondary
After-tax cash from secondary today
$0
If QSBS qualifies:$0
If not QSBS:$0
QSBS "Not sure" note: Scenario A is shown conservatively as non-QSBS unless you explicitly select "Yes, likely QSBS".
After-tax value at exit (secondary path)
$0
Exit value (QSBS):$0
Exit value (not QSBS):$0
QSBS scenario assumes the holding period is met for the secondary sale date, and applies the cap rules in this tool.
Tax on the secondary (federal + NIIT + state)
$0
By default, proceeds are treated as cash (0% growth). If reinvestment is on, we grow after-tax proceeds at your selected rate.
Scenario B: Hold this block to exit
After-tax value at exit (hold path)
$0
Implied after-tax IRR from holding (base case)
N/A
IRR here is the annualized after-tax return from holding instead of selling now (and reinvesting proceeds if enabled).
QSBS benefit level at exit (high level)
N/A
If QSBS qualifies:$0
If not QSBS:$0
This does not change your inputs. It shows a range when QSBS status is uncertain.
Difference at exit (base case)
Hold vs sell, after-tax $ difference
$0
Hold vs sell, % difference
N/A
This highlights whether incremental upside from holding compensates you for illiquidity and risk.
Pressure test: exit value slider
Move the slider to see how sell vs hold changes when the exit outcome is better or worse than the base case.
Exit multiple: 1.00x
Exit value: $0
Important: This tool applies a single per-issuer QSBS cap for a single taxpayer profile in each scenario, using the greater of (i) the applicable statutory dollar cap ($10M for legacy QSBS, $15M for post-OBBBA QSBS) or (ii) 10x basis. It does not model QSBS stacking or multi-taxpayer structuring.
This is a simplified, educational tool. It assumes federal long-term capital gains at 20% plus 3.8% NIIT on taxable gain. For legacy 50% and 75% QSBS, it applies a rough AMT preference approximation. If a sale occurs within one year of acquisition, it treats that as short-term and applies a 37% ordinary income rate plus NIIT on taxable gain, with no QSBS exclusion modeled. State tax is modeled only using the simple presets above. This is not tax, legal, or investment advice.
Important: Disclaimers
This calculator and information are for educational and illustrative purposes only and do not constitute tax, legal, or financial advice. Calculations involve complex federal and state rules that vary based on individual circumstances. Tax calculations and QSBS rules are complex and subject to specific requirements and limitations. Consult with qualified tax and legal professionals regarding your specific situation.
Message to Keystone GP
Copy this message and paste it into our form. It includes your inputs, results, and assumptions.