And how to actually get an accurate number
Tax brackets shift with inflation every year. Plugging in old numbers can throw your estimate off by hundreds of dollars.
401(k) contributions, HSA payments, and pre-tax insurance premiums lower your taxable income before tax is even calculated.
A federal-only estimate can miss a big chunk of what actually comes out of your paycheck, especially in higher-tax states.
Getting married, having a dependent, or changing your withholding all shift which bracket you land in. Recalculate when life changes.
A calculator is a planning tool. It gets you close, but your actual return can differ once every deduction is filed.
Free, primary-source-cited paycheck and tax calculators for 16 countries — pennycompass.com