Bonus Gross Up Calculator

Gross-up a bonus to ensure your employee receives the exact net amount. Handles federal supplemental rate, state/local withholding, Social Security cap, and Additional Medicare tax.

Bonus details

Specify the cash you want the employee to take home, then layer in withholding assumptions.

Social Security is capped at the wage base; Additional Medicare applies once the YTD+bonus exceeds $200,000.

How to Use This Calculator

Begin by entering the exact net bonus you want the employee to receive. Configure the supplemental rate plus any state or local withholding that applies, then toggle the FICA settings to model Social Security and Medicare contributions.

Methodology

The calculator iteratively solves for the gross bonus amount that, once all withholding is applied, leaves you with the requested net. FICA contributions observe the wage base cap, and the 0.9% Additional Medicare tax kicks in if the combined YTD wages plus the bonus surpass $200,000.

Results are estimates and may differ from payroll provider quotes. Consult your payroll service or advisor to validate specifics.

Why use this gross-up tool

  • Handles FICA caps and Additional Medicare correctly.
  • Flat supplemental rate method aligned with IRS rules.
  • Clear breakdown and effective rate for documentation.

Full original guide (expanded)

The legacy page also surfaced a few ancillary references, such as ad placements and related payroll resources that remain documented here for completeness.

Related payroll tools

Ad placement

The original layout reserved a 300×600 placeholder for an ad unit (used for audit review). The space is noted here as a reminder of the legacy scaffolding.

Formulas

Formula (extracted text)

\( \displaystyle \text{Gross} = \frac{\text{Net}}{1 - (r_f + r_s + r_l + r_{fica})} \)

Formula (extracted text)

\( \displaystyle \text{Find Gross such that } \text{Net} = \text{Gross} - W(\text{Gross}) \)

Variables and units

  • T = property tax (annual or monthly depending on input) (currency)
Citations

Sources (authoritative):

Changelog
Version: 0.1.0-draft
Last code update: 2026-01-19
0.1.0-draft · 2026-01-19
  • Initial audit spec draft generated from HTML extraction (review required).
  • Verify formulas match the calculator engine and convert any text-only formulas to LaTeX.
  • Confirm sources are authoritative and relevant to the calculator methodology.
Verified by Ugo Candido Last Updated: 2026-01-19 Version 0.1.0-draft
Version 1.5.0