Illinois Paycheck Calculator: Your After-Tax Pay Explained
Illinois uses a flat state income tax rate that applies equally to all income levels, which makes it one of the more straightforward states to estimate compared to states with multiple progressive brackets. Here's exactly what shapes an Illinois paycheck. What comes out of an Illinois paycheck Every Illinois paycheck includes: Federal income tax — based on income, filing status, and W-4 elections Illinois state income tax — a flat rate applied to all taxable income, regardless of how much you earn Social Security tax — 6.2% on wages up to $184,500 for 2026 Medicare tax — 1.45% on all wages, no cap Worked example: $65,000 salary in Illinois Single filer, paid biweekly (26 pay periods), no pre-tax deductions: Federal standard deduction (2026): $16,100 Federal taxable income: $48,900 Federal tax owed: 10% on $12,400 ($1,240) + 12% on $36,500 ($4,380) = $5,620 Social Security: 6.2% × $65,000 = $4,030 Medicare: 1.45% × $65,000 = $942.50 Illinois state in...