Tested tool guide
Tested browser tools
Checked August 16, 2026
What Payroll Calculator does, with a checked example
Enter a gross pay amount, its pay period, a filing status, and a state, and the Payroll Calculator returns a full gross-to-net statement: federal income tax withheld, the employee's Social Security and Medicare shares, state withholding, the effect of pre-tax deductions, and net take-home, then the employer's matching FICA and total pay-period cost. Federal withholding follows the IRS percentage method, so it is computed on annualized pay against the standard deduction, not by applying your tax bracket to a single check. The surprise most people hit: pre-tax deductions such as a 401(k) or HSA lower federal and state withholding, but Social Security and Medicare still hit your full gross.
Worked example
A concrete input and expected output from the current implementation.
Input
Monthly gross pay: $1,200.00. Filing status: Single. State: Washington (no state income tax). W-4: standard, no extra withholding. Pre-tax deductions: none.
->
Expected output
Gross pay $1,200.00 | Social Security $74.40 | Medicare $17.40 | Federal income tax $0.00 | State income tax $0.00 | Total deductions $91.80 | Net pay $1,108.20 | Employer Social Security $74.40 | Employer Medicare $17.40 | Total employer cost $1,291.80
Annualized at $14,400, this income sits below the single standard deduction, so federal withholding is $0 under any recent table year; Social Security (6.2 percent) and Medicare (1.45 percent) are flat rates below the wage cap, and Washington has no state income tax, so every figure is exact. The employer pays an equal FICA match of $91.80, making total cost $1,200 plus the match.