USA Federal Salary Calculator
Federal Tax, Social Security and Medicare

How US Federal Salary Tax Works

A federal salary estimate starts from gross salary, subtracts any modeled pre-tax 401(k) contribution from income used for federal tax, applies the standard deduction for the filing status, and then runs the remaining taxable income through the federal tax brackets. Payroll taxes for Social Security and Medicare are separate and should be shown separately from federal income tax.

Standard Deduction Explained

The standard deduction is a fixed amount that reduces the income exposed to federal income tax. It depends on filing status. A larger standard deduction lowers federal taxable income and can materially reduce total federal income tax.

Social Security and Medicare Explained

Social Security and Medicare are payroll taxes under FICA. Social Security has a wage base cap, which means the tax stops after wages reach the annual cap. Medicare has no wage cap, so it continues to apply to all covered wages. This is why payroll deductions can keep rising even after Social Security maxes out.

Additional Medicare Tax Explained

An extra 0.9% Additional Medicare Tax can apply when Medicare wages exceed the filing-status threshold. In this calculator, the threshold is based on filing status and the additional amount is shown separately from the base Medicare tax so the user can see exactly when it starts to matter.

401(k) Contribution Explained

A pre-tax 401(k) contribution generally lowers the income used for federal income tax, which can reduce federal tax. But it still lowers take-home pay because the money is being set aside for retirement instead of being received as cash now. This V1 calculator keeps the treatment simple and does not reduce FICA wages with the 401(k) input.

Frequently Asked Questions