Tax year 2026
Last verified:
Effective period: 1 January 2026 to 31 December 2026
The calculator uses the 2026 IRS Publication 15-T Percentage Method for Automated Payroll Systems for federal withholding, the 2026 employee FICA rates and thresholds, and a verified batch of 19 state withholding modules — see below for exactly which layers are supported.
Federal withholding
Federal income-tax withholding follows Publication 15-T (2026) Worksheet 1A exactly: annualize the pay-period wage, apply Form W-4 Step 4(a)/(b) adjustments, look up the tentative annual withholding in the Percentage Method table for the selected filing status and Step 2 schedule, subtract Step 3 credits (floored at $0), divide back to the pay period, then add Step 4(c) extra withholding. Supplemental wages use the aggregate or flat (22%/37% above $1,000,000 cumulative) method.
Social Security and Medicare
Social Security withholds at 6.2% up to the $184,500 annual wage base; Medicare withholds at 1.45% with no ceiling, plus 0.9% Additional Medicare on wages from one employer above $200,000 in the year. Only employee-side FICA is ever subtracted from net pay.
State coverage
19 of 51 jurisdictions (50 states + DC) are supported: 9 states verified to have no broad wage income tax (Alaska, Florida, Nevada, New Hampshire, South Dakota, Tennessee, Texas, Washington, Wyoming), plus 10 states with verified 2026 flat or progressive withholding data (Arizona, California, Colorado, Illinois, Indiana, Kentucky, Michigan, New York, Pennsylvania, Utah). The remaining 32 states and DC return a federal-and-FICA-only estimate with an explicit partial-support warning, never a silently assumed $0.
Local coverage
No city, county, or occupational local tax is modeled yet (New York City, Yonkers, Philadelphia, Ohio municipalities, and Pennsylvania local Earned Income Tax are all named as future work) — every locality lookup returns an explicit unsupported warning.