Estimate annual Illinois state income-tax withholding on wages.
A simplified Illinois state income-tax withholding estimate on gross wages using an approximate rate. State withholding estimated using an approximate flat/top rate. Real withholding depends on official state tables.
Withholding
Withholding ≈ (wages − standard deduction) × approximate state rate
Approximate reference estimate only — not an official payroll calculation.
Most states publish percentage-method and wage-bracket tables. This tool applies an approximate reference rate; confirm with the state revenue department.
Rates are approximate state or national reference values. Local rates, exemptions and rules can differ, so treat the output as a planning figure only.