# Methodology and sources

Updated for tax year 2026 (IRS Rev. Proc. 2025-32). Last updated August 24, 2026. Takehome Cash is an estimate of typical W-2 withholding, not tax-preparation software.

## Federal income tax (2026)

Brackets and standard deductions come from the IRS newsroom release on tax year 2026 inflation adjustments (including OBBBA) and Revenue Procedure 2025-32. Rates remain 10, 12, 22, 24, 32, 35, and 37 percent. Standard deduction: $16,100 single and married filing separately; $32,200 married filing jointly; $24,150 head of household.

We assume the standard deduction. We do not model itemizing, AMT, NIIT, or the Child Tax Credit.

## Social Security and Medicare

Social Security (OASDI) employee rate 6.2% on wages up to the SSA 2026 contribution and benefit base of $184,500. Medicare 1.45% on all FICA wages. Additional Medicare Tax 0.9% above $200,000 (single / head of household), $250,000 (married filing jointly), or $125,000 (married filing separately). Traditional 401(k) deferrals stay in the FICA base; cafeteria-plan health premiums come out.

## State income tax

Rates, brackets, standard deductions, and personal exemptions are taken from the Tax Foundation “2026 State Income Tax Rates and Brackets” table (as of January 1 / February 11, 2026 compilation of state statutes). No-tax wage states: AK, FL, NV, NH, SD, TN, TX, WY, and WA (wages only). Washington’s capital-gains tax is not applied to W-2 pay.

Head of household uses each state’s single-style brackets with the listed HOH or single standard deduction. Married filing separately uses single brackets. Credits listed as personal exemptions are subtracted from tax; deduction-style exemptions reduce taxable income. Utah’s taxpayer credit is applied without its phaseout.

## Changelog

- 2026-08-24: About rewrite; noindex on markdown twins; shareable calculator URLs; optional NYC resident tax; CA SDI 1.3%; WA Cares 0.58%; bonus/supplemental mode; in-tool state compare.

## Known gaps

- California, Massachusetts, North Dakota, Idaho, Vermont: some 2026 inflation-adjusted bracket or deduction widths were unpublished; Tax Foundation shows 2025 widths.
- Connecticut and New York: benefit recapture is not fully modeled.
- Maine, Minnesota, Rhode Island, Wisconsin, Utah: deduction/credit phaseouts omitted or simplified.
- Arkansas: lower-income alternate table simplified to the 2% / 3.9% structure.
- South Carolina: 6.0% top rate is temporary through June 30, 2026.
- Local taxes omitted except an optional NYC resident checkbox (2025 published city schedule). MD counties, OH cities, PA EIT, IN counties still omitted.
- CA SDI (1.3%, no ceiling) and WA Cares (0.58%, optional) are separate lines when those states are selected.

## Primary sources

- [IRS newsroom — 2026 inflation adjustments](https://www.irs.gov/newsroom/irs-releases-tax-inflation-adjustments-for-tax-year-2026-including-amendments-from-the-one-big-beautiful-bill)
- IRS Revenue Procedure 2025-32
- [SSA contribution and benefit base](https://www.ssa.gov/oact/cola/cbb.html)
- [Tax Foundation 2026 state rates and brackets](https://taxfoundation.org/data/all/state/state-income-tax-rates-2026/)