Illinois · rates effective Jan 1 – Dec 31, 2026 · verified 2026-08-05
Illinois Paycheck Calculator 2026
4.95% flat state tax rate in Illinois — no local income tax, no state payroll deduction.
Illinois taxes wages at a flat 4.95%, from the first taxable dollar - there is no standard deduction and no lower bracket to ease you in. What actually lands on your stub depends on the two different allowance lines of Form IL-W-4, which are worth $2,925 and $1,000 apiece. This calculator runs the state's own booklet formula.
Official 2026 tables, never copiedSources stamped & dated99 golden tests before publish
CEBy the Calceva data desk · Verified against official sources · Updated 2026-08-05 · 3 min read
Illinois is one of the simplest states to describe and one of the easiest to get slightly wrong. The rate never changes with income, so the arithmetic lives entirely in what gets subtracted first. Form IL-W-4 has two allowance lines and they are not worth the same: each Line 1 allowance (you, your spouse, your dependents) shields $2,925 a year, while each Line 2 allowance (age 65 or over, or legally blind) shields $1,000. Add them, divide by your number of pay periods, subtract, then apply 4.95%. A single filer claiming one Line 1 allowance on a $60,000 salary is withheld on $57,075, not $60,000 - about $145 a year less than the headline rate suggests.
What we check this page against
Booklet IL-700-T prints one worked example and pages of withholding tables. We rebuilt every one of the 1,436 published table cells from the state’s own automated payroll formula, and all 1,436 match; a sample of them runs as tests on every release, so a drifting rate cannot slip through behind a single rounded example. Two things that exercise corrected our own assumptions: the published tables do not round the exemption to the cent, and Illinois divides the annual exemption by 365 days for a daily payroll rather than by working days. Both are in the calculator above.
One line you will not find on an Illinois stub is a local one: no municipality in the state taxes wages, which is why our Chicago page shows the same state lines as this one. If you are comparing offers across state lines, the flat rate cuts both ways - it is gentle at high salaries and unusually heavy at entry level.
No. Illinois has no standard deduction at all. The only thing between your wages and the 4.95% rate is the allowance total from Form IL-W-4 - $2,925 per Line 1 allowance and $1,000 per Line 2 allowance.
What is the difference between Line 1 and Line 2 on Form IL-W-4?
Line 1 covers personal and dependent allowances and is worth $2,925 each. Line 2 covers additional allowances for being 65 or over, or legally blind, and is worth $1,000 each. Employers must keep them separate: mixing them up changes your withholding.
Does any Illinois city or county tax my paycheck?
None. Illinois municipalities are not permitted to tax wages, so a paycheck in Chicago, Rockford or Springfield carries the same state line - only property and sales taxes differ locally.
Why is my Illinois withholding a little different from my final tax bill?
Withholding follows the employer formula in Booklet IL-700-T, which knows only your wages and your IL-W-4. Your return applies credits and other income the payroll formula never sees, so the two figures settle up at filing time.
We never copy another calculator. Each rate is read from the official document, dated, and re-checked when agencies publish changes. This page's paper trail:
IDOR Informational Bulletin FY 2026-15 — 2026 exemption allowance $2,925 per allowance; additional 65+/blind allowance $1,000/yr. No standard deduction. Chicago and all IL municipalities: NO local income tax on wages.
Verified 2026-08-05
Illinois Booklet IL-700-T (R-12/25) — Withholding (automated payroll method, IL-700-T R-12/25): exemptions = Line 1 allowances x $2,925 plus Line 2 allowances x $1,000, divided by the number of pay periods; withholding = (wages - exemptions) x 4.95%. Reproduces the booklet's worked example to the cent.
Verified 2026-08-05
IDOR, Form IL-W-4 (R-07/23), served as the current-year form (PDF read in full, 2 p.) — Illinois withholding is set by Form IL-W-4, "Employee's and other Payee's Illinois Withholding Allowance Certificate and Instructions"; the number of allowances on Line 1 sets the base amount withheld, Line 2 allowances are subtracted from it and Line 3 adds a flat extra amount per pay period.
Federal lines
Federal income tax, Social Security and Medicare on this page follow IRS Rev. Proc. 2025-32, Publication 15 and Publication 15-T, verified 2026-08-07. Our federal engine reproduces 2,175 of 2,175 Publication 15-T cells on every build. The six federal sources, itemised.
Matches the agency
Reproduces the agency’s own published figures. Our implementation of the Illinois withholding formula reproduces all 19 published figures — 1 worked example and 18 cells of the official wage-bracket tables of Illinois Booklet IL-700-T (R-12/25), automated payroll method exactly as the agency prints them, re-checked on every build. Check them in the official PDF.
Cite this pageCalceva, “Illinois Paycheck Calculator (2026),” verified 2026-08-05, https://calceva.com/illinois-paycheck-calculator/