Methodology
Every dollar amount is an integer number of cents. Rates use half-up rounding. A line is either an employer method we transcribed or a statutory estimate, and the page says which.
Federal income tax
Federal withholding is IRS Publication 15-T (2026) Worksheet 1A, the percentage method. Pay periods are 52, 26, 24, 12, 4, 2, 1, and 260. Line 1g is $12,900 for married filing jointly and $8,600 otherwise, or zero if Step 2 is checked. A 2019 or earlier W-4 uses $4,300 per allowance and the single table for every status, including head of household.
The optional nearest-dollar toggle is off unless you turn it on. Displayed cents are the default.
FICA and pre-tax amounts
Social Security is 6.2% up to $184,500, a maximum of $11,439. Medicare is 1.45%. Additional Medicare is 0.9% after $200,000 from one employer. With no year-to-date entry, this paycheck withholds the full 6.2% and no Additional Medicare unless the check itself crosses a threshold.
Traditional 401(k) deferrals reduce federal income tax and not FICA, and they are spread under the $24,500 cap. Cafeteria amounts reduce federal income tax, FICA, and state wages. Roth and other post-tax amounts reduce net pay only. Pennsylvania pages note that some stubs still tax 401(k) deferrals. Set the percent to zero to match that stub.
States, cities, and payroll programs
Bracket states other than California use the Tax Foundation table as of January 1, 2026, after the published standard deduction and exemption. That is not the employer wage table. Head of household and married filing separately use the single brackets except in California.
Philadelphia uses 3.74% and 3.43% through June 30, 2026, then 3.735% and 3.425%. New York City resident rates are applied to New York taxable income and are not labeled as the NYS-50-T-NYC table. Yonkers residents pay 16.75% of the state tax. Nonresidents pay 0.50% of wages.
Included payroll lines: California SDI 1.3%, Washington PFML at the employee share of the 1.13% premium up to $184,500, WA Cares 0.58% with a note to confirm it with Washington, Minnesota Paid Leave up to 0.44% and $814, New York Paid Family Leave 0.432% up to $411.91, New Jersey TDI 0.19% and FLI 0.23% up to $171,100, and Massachusetts PFML 0.46%.
Sources
- IRS Publication 15-T (2026)
- IRS Publication 15 (2026)
- Social Security Administration, contribution and benefit base
- IRS, Additional Medicare Tax
- IRS, tax year 2026 inflation adjustments
- IRS, 2026 retirement plan limits
- IRS, no tax on overtime deduction
- Tax Foundation, state income tax rates and brackets, 2026
- California EDD, 2026 withholding schedules, Method B
- California EDD, payroll tax rates
- Illinois Department of Revenue, 2026 IL-700-T
- City of Philadelphia, wage tax for employers
- Washington Paid Family & Medical Leave
- New York Paid Family Leave, 2026
- New Jersey Department of Labor, employer rates
- Massachusetts PFML contributions
- Minnesota Paid Leave premium calculator
- IRS, earned income tax credit
Questions
What is half-up rounding?
When a remainder is at least half a cent, we round away from zero. Philadelphia’s $2,500 resident check on July 15, 2026 is $93.38 for that reason.
Why can the year differ from the paycheck times the number of periods?
Social Security stops at $184,500 and Additional Medicare starts after $200,000. Those annual rules are on the year summary, not forced onto a small check.
Which state figures are withholding?
California EDD Method B, Illinois 4.95% after the $2,925 allowance, Pennsylvania 3.07%, Arizona’s elected percent, and the nine states with no wage tax.
What did we leave out on purpose?
Unverified programs, including New York disability, several paid-leave programs, and local rates we could not cite. Those lines are omitted rather than guessed. Connecticut recapture is not modeled.