Disclaimer

What "estimate" means here

The calculator applies the federal, FICA and state rules published for the tax year shown on the page to the figures you enter. Where those rules are unambiguous — the Medicare rate, the Social Security wage base, the federal brackets for your filing status — the arithmetic is exact. What cannot be exact is the match between your real payroll run and a page that knows only what you typed into it.

Why your actual paycheck may differ

• Your employer's payroll system. Payroll software applies its own withholding method and its own rounding, period by period. Two systems can produce slightly different withholding from identical inputs, and both can be correct.
• The W-4 you actually filed. Dependent credits, the multiple-jobs checkbox, other income, extra deductions and additional withholding all change what is taken out. This calculator models filing status and additional withholding; it does not reproduce every line of your W-4.
• Timing within the year. The Social Security wage base and the Additional Medicare threshold are annual. Benefits that start, stop or change mid-year, and raises that take effect partway through, shift the result for individual paychecks even when the annual total matches.
• Bonuses and commissions. Employers often withhold these as supplemental wages at a flat rate, or by treating the payment as if it were your regular pay for every period. Either method withholds differently from the annual calculation shown here. The difference is settled when you file.
• Local taxes. Thousands of municipalities, counties and school districts levy their own income taxes, and which one applies can depend on where you live as well as where you work. The calculator covers the major ones and lets you enter a local rate directly; it cannot enumerate every jurisdiction.
• Deductions we cannot see. Union dues, garnishments, loan repayments, equity purchase plans, parking, and employer-specific benefits all come out of real paychecks. Enter them under Advanced Options if you want them counted.
• Year-end reconciliation. Withholding is a prepayment, not a final tax bill. Credits, itemized deductions, other income and a spouse's earnings are all settled on your return.

How the tax data is maintained

Rates, brackets, standard deductions and thresholds come from the Internal Revenue Service and from each state's own revenue or taxation authority. Every value is stored with the source it came from, the tax year it applies to, and the date it was last checked.

Some states legislate a rate for the coming year before publishing final inflation-adjusted brackets. In those cases the most recently published brackets are carried forward and marked as carried forward, rather than being invented. Figures are never estimated to fill a gap silently.

Even so, tax rules change, agencies issue corrections, and errors are possible. If a figure looks wrong to you, trust your payslip and the relevant agency over this site.

Not professional advice

Nothing on CalcPaid is tax, legal, accounting or financial advice, and nothing here is tailored to your circumstances. Do not use it as the sole basis for filing a return, accepting or declining a job, setting contribution rates, or any other consequential decision. Speak to a qualified professional, or to your employer's payroll department, who can see the whole picture.

No liability

CalcPaid is provided free and as-is. We accept no liability for decisions made on the basis of its output. The Terms of Use set this out in full.