Illinois Biweekly Paycheck Calculator 2026

Here is exactly what your biweekly paycheck looks like in Illinois at common annual salary levels in 2026. Calculated for a single filer, standard W-4, biweekly pay frequency, no pre-tax deductions.

Single filer · standard W-4 · biweekly pay (26 periods/yr) · no pre-tax deductions · 2026 IRS withholding tables · Illinois published 2026 withholding method. Actual paychecks vary based on filing status, allowances, and deductions.

Illinois withholds state income tax from every paycheck. Your biweekly paycheck includes these deductions:

• Federal income tax (2026 IRS withholding tables)
• Illinois state income tax (withheld each pay period)
• Social Security tax — 6.2% on wages up to $184,500
• Medicare tax — 1.45% on all wages
• Employee benefit deductions

A biweekly pay schedule means you receive a paycheck every two weeks — 26 paychecks per year. To find your gross biweekly pay, divide your annual salary by 26:

Two months per year you will receive three biweekly paychecks instead of two. This is sometimes called a "three-paycheck month." Because benefit deductions are often fixed per paycheck, the extra check can feel larger than usual.

Your net biweekly paycheck in Illinois depends on your annual salary, W-4 filing status, Illinois state withholding elections, retirement contributions, health insurance deductions, and any additional withholding.

Illinois applies a single 4.95% rate after subtracting $2,925 of annual exemption per IL-W-4 allowance, exactly as the calculator above does. There are no brackets to cross, so unlike almost every other taxing state, an Illinois worker's state withholding rises in a straight line with gross pay.

On a biweekly schedule this makes Illinois unusually predictable: the state line on paycheck 26 is the same percentage of gross as the line on paycheck 1, and a raise changes it proportionally rather than disproportionately. It is the federal line that does the bracket-crossing on an Illinois stub, not the state one.

The $2,925 annual exemption per allowance, divided across 26 pay periods, removes roughly $112 of taxable wage from each biweekly paycheck. At 4.95% that is around $5.57 of withholding per allowance per check, or about $145 over the year.

Because the rate is flat, this arithmetic holds at every salary — an allowance is worth the same to an Illinois worker earning $40,000 as to one earning $200,000. That is not true in any bracketed state, and it makes the effect of an IL-W-4 change easy to verify against your own stub.

Illinois maintains reciprocal agreements with Iowa, Kentucky, Michigan and Wisconsin. A resident of one of those states working in Illinois files Form IL-W-5-NR to stop Illinois withholding, and an Illinois resident working in one of them files the equivalent certificate there. Only your home state withholds.

Indiana and Missouri are not on that list, despite both bordering Illinois. A cross-border commute to St. Louis or into Indiana therefore means withholding from both states on all 26 checks, with an Illinois credit claimed at filing to unwind it.