This calculator uses IRS-published federal income tax brackets and standard deductions for the selected tax year. Federal tax applies to taxable income β your gross salary minus the standard deduction and any pre-tax deductions. Social Security (6.2%) and Medicare (1.45%) are calculated on your full gross salary, with Social Security capped at the annual wage base. State tax is estimated using your state's published rate and is shown as an approximation β actual liability will depend on your state's own deductions, credits, and filing rules. This calculator assumes you take the federal standard deduction.