83(b) Election Cost Calculator
Drag the two dots to set what your stock was worth at grant and what it might be worth once it's fully vested. The gap between the lines is what gets taxed as ordinary income if you miss the 30-day window to file.
File within 30 days: taxed on $0.0010/share now — about $32 total, and nothing more as it vests.
Miss the window: taxed on $2.00/share as it vests instead — about $64,000 total, on stock you likely can't sell yet to cover the bill.
Simplified: assumes a blended 32% ordinary-income rate and treats the vested value as taxed all at once rather than in pieces across your vesting schedule. Your actual bracket, state taxes, and AMT exposure will move the real number. The 30-day deadline itself isn't simplified — it's a hard legal window with no extensions.
An 83(b) election lets you pay ordinary income tax on stock at its value on the day it's granted, instead of waiting until it vests — locking in today's, often much lower, value instead of a future one. On stock worth $5,000 at grant that's worth $50,000 once fully vested, filing within the window means paying tax on $5,000 (about $1,600 at a 32% rate); missing it means paying tax on the full $50,000 vested value (about $16,000) — a difference of roughly $14,400.
The IRC §83(b) filing deadline is a hard 30-day cutoff from the grant date, with no extensions — missing it isn't fixable after the fact.
Just got a grant? Don't find out about this in year two.
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