US payroll deductions explained
US payroll can combine federal income tax withholding with state, local, and employee FICA deductions. The same salary can therefore produce different take-home pay in different locations and for different employee circumstances.
Federal withholding is one part of the picture
Federal income tax withholding is influenced by the information an employee provides for payroll, including the Form W-4 process. It is a withholding calculation, not necessarily the final tax result for the year. Filing status, dependants, other income, deductions, and credits can change the eventual tax position.
A calculator can provide a standard planning estimate using reference bands. It cannot replace a personal withholding worksheet or a filed federal return.
State and local taxes can change the result
State income-tax systems differ significantly. Some locations may also have local or city payroll taxes. Selecting the correct state is therefore important for a useful comparison, and a move within the United States can change take-home pay even when gross salary stays the same.
FICA is separate from income tax
Employee Social Security and Medicare contributions are commonly shown separately on a US payslip. Their calculation can use different thresholds and caps from federal income tax. Employer contributions are also separate from employee deductions and should not be treated as money that reaches your paycheck.
Check the pay frequency and benefits
A US offer may be quoted annually while payroll is paid biweekly, semimonthly, or monthly. Health insurance premiums, retirement-plan contributions, commuter benefits, and other elections can materially change net pay. Ask whether premiums are pre-tax or post-tax and whether the employer contribution is included in the offer summary.
For federal guidance, check United States IRS. Use the relevant state and local authority for location-specific requirements.