How Accurate Are Online Paycheck Calculators?
Online paycheck calculators are genuinely useful — but it's fair to wonder how close their numbers actually get to your real paycheck. Here's what goes into the calculation, where accuracy holds up well, and where it naturally has limits. What a good paycheck calculator gets right A well-built calculator applies the same core rules your employer's payroll system does: Current IRS tax brackets and standard deductions for the selected tax year FICA rates — 6.2% Social Security (up to the annual wage cap) and 1.45% Medicare State income tax rules , including whether a state has no tax, a flat rate, or progressive brackets Pay frequency math — converting annual figures into biweekly, weekly, or monthly amounts correctly For a straightforward W-2 employee with a standard salary and no unusual deductions, a good calculator should land very close to your real paycheck — typically within a few dollars, assuming the inputs are accurate. Where calculators are natura...