ABOUT METHODOLOGY & SOURCES

About goldenhandcuffs.fyi

An independent RSU tax calculator built to help tech employees estimate their supplemental withholding gap before April.

1. Why This Site Exists

Equity compensation makes up a large share of total pay in tech, yet every spring, software engineers, product managers, and tech leads get caught off guard by five-figure tax bills and IRS underpayment penalties (Form 2210).

The reason is built into the tax code: under IRC § 3402(g) and Treasury Regulation § 31.3402(g)-1, stock plan brokerages withhold a flat 22% on supplemental RSU wages up to $1,000,000. For employees whose total income puts them in the 32%, 35%, or 37% federal bracket—plus progressive state brackets in California, New York, or Massachusetts—default sell-to-cover withholding leaves a 10% to 15% tax shortfall on every vest.

Browser-Local Calculations: All calculator inputs (salary, share counts, and state selection) run directly in your browser. We never collect, transmit, or store the numbers you enter.

2. Author

goldenhandcuffs.fyi was built and is maintained by Sean Beck, a software engineer focused on financial modeling and tax software.

The calculation engine is tested against 2026 FICA wage caps, multi-tier supplemental withholding thresholds ($1,000,000 IRC § 3402(g) cliff), progressive federal brackets, and state supplemental withholding schedules.

3. Primary Tax Sources & Funding

All tax rates and RSU Tax Guides on this site are referenced from federal and state government publications:

Federal Statutory Authorities: Internal Revenue Code §§ 83, 1012, 1091, 3101(b)(2), 3402(g), 409A, and 6654; Treasury Regulation § 31.3402(g)-1; IRS Publication 15 (Circular E); and IRS Publication 505 (Tax Withholding and Estimated Tax).
Social Security & Medicare Parameters: Social Security Administration (SSA) OASDI Contribution and Benefit Base ($184,500 cap for 2026) and IRS Form 8959 (0.9% Additional Medicare Tax thresholds).
State Revenue Authorities: California Franchise Tax Board (FTB Publication 1004 & Form 540-ES instructions), New York State Department of Taxation and Finance (TSB-M-07(7)I & Form IT-2105), Massachusetts Department of Revenue (830 CMR 62.5A.1 & Fair Share Amendment guidelines), and Washington Department of Revenue (RCW 82.87 Capital Gains Excise Tax).
Editorial Independence & Site Funding: All calculators and guides are free to use with no sign-up required. The site is funded through display advertising (Google AdSense).

4. Contact & Statutory Corrections

We welcome feedback from tax practitioners, corporate stock plan administrators, and software engineers. To report a statutory rate update or inquire about our methodology, visit our Contact & Inquiries page or email support@goldenhandcuffs.fyi.