The official sources behind our calculators and guides.
Federal
- IRS: tax inflation adjustments for tax year 2026 (brackets and standard deductions)
- IRS Revenue Procedure 2025-32 (2026 rate tables for every filing status)
- IRS Publication 15-T, Federal Income Tax Withholding Methods
- Social Security Administration: contribution and benefit base (2026 wage base $184,500)
States
- Tax Foundation: State Individual Income Tax Rates and Brackets, 2026 (rates, brackets, standard deductions, exemptions and credits for every state, compiled from state statutes and revenue departments; published February 2026)
State payroll contributions included in the calculator are those set by state law; see the calculation methodology for the list.
Retirement and health accounts
- IRS: 2026 401(k) and IRA limits
- IRS Revenue Procedure 2025-19 (2026 HSA limits)