Calculators
These calculators provide educational estimates and can be wrong depending on your personal situation (state taxes, deductions, credits, filing status, holding periods, and more). If the number is big, talk to a CPA.
Equity calculator (startup / private)
Quick scenarios. This does NOT account for liquidation preferences, taxes, or lockups.
Inputs
Tip: try 20–40% dilution for a couple more rounds.
Results
Vested shares
2,500
After vesting fraction (25%)
Effective shares (after dilution)
2,000
Assumes 20% dilution
Value today
$2,000
Value at exit
$18,000
Exercise cost (if exercised)
$2,000
Taxes not included.
Learn more in the FAQ.
RSU calculator
Estimates gross value at vest and an estimated withholding amount.
Inputs
Many employers withhold at a default supplemental rate, but your true tax may differ.
ISO / AMT exposure (rough estimate)
Uses IRS-published 2026 AMT parameters. This is simplified and does not include every AMT adjustment or credit.
Inputs
ISO exercise
AMT can also be affected by other items (example: SALT deductions). This calculator doesn't capture everything.
Results
ISO bargain element (AMT income)
$9,000
AMTI (approx)
$159,000
AMT exemption (after phase-out)
$90,100
Tentative minimum tax (AMT)
$17,914
Regular tax (estimated)
$28,598
Estimated incremental AMT due
$0
Note: ISO AMT can be a timing issue; you may be eligible for an AMT credit later.
Sources: IRS AMT inflation adjustments (TY 2026) and IRS stock option guidance.
NSO calculator
Estimates ordinary-income taxes on the spread at exercise.
Inputs
This can include federal + state + payroll, depending on how you want to approximate.
Results
Spread
$9,000
Exercise cost
$1,000
Est. tax at exercise
$3,330
Est. cash needed
$4,330
Source: IRS Topic 427 (nonstatutory options are generally taxable at exercise when FMV is not readily determined).
More help
If you want, I can add:
- Vesting schedule timeline outputs
- Capital gains estimates on sale
- A "cashless exercise" scenario