Methodology

Formulas

These pages use rules US-2026, revision 1, last reviewed on November 12, 2026.

• Standard deduction: $16,100 (single), $32,200 (married filing jointly), $24,150 (head of household).
• Federal income tax, Single, on income after the standard deduction (shown as salary): 10% up to $28,500; 12% up to $66,500; 22% up to $121,800; 24% up to $217,875; 32% up to $272,325; 35% up to $656,700; 37% above $656,700.
• Federal income tax, Married filing jointly, on income after the standard deduction (shown as salary): 10% up to $57,000; 12% up to $133,000; 22% up to $243,600; 24% up to $435,750; 32% up to $544,650; 35% up to $800,900; 37% above $800,900.
• Federal income tax, Head of household, on income after the standard deduction (shown as salary): 10% up to $41,850; 12% up to $91,600; 22% up to $129,850; 24% up to $225,900; 32% up to $280,350; 35% up to $664,750; 37% above $664,750.
• FICA: Social Security is 6.2% of wages up to $184,500; Medicare is 1.45% of all wages, plus 0.9% on wages over $200,000 (single, head of household) or $250,000 (married filing jointly). FICA applies to wages before 401(k) deferrals.
• Traditional 401(k) deferrals reduce federal taxable income, up to the annual limit of $24,500.
• State income tax is not included unless you pick a state with no wage tax (9 states) or enter your own flat rate, which is labelled as your estimate.
• Married filing jointly treats the household as a single earner for Social Security and Medicare; the wage cap and extra Medicare tax apply per earner in payroll.

Rounding and scope

Each line item is rounded to the nearest cent or penny. Results are annual estimates of tax liability, not payroll deductions, so they can differ from a payslip by small amounts. Pages show the version of the rules they used.

The official sources for these rules are listed on the Sources page. Sources