Illinois 1099 Tax Calculator (2026)
Illinois taxes all income at a flat 4.95%, so your total tax burden is three layers: the federal self-employment tax, federal income tax, and this one flat state rate. The calculator below is already set to $55,000 of 1099 income, filing single, state = IL. Change any field to match your own numbers.
Self-employment tax
$7,771
15.3%, federal
Federal income tax
$2,727
on $24,791 taxable
Illinois income tax
$2,385
4.95% of $48,189
Total tax
$12,884
23% of gross — set that much aside
Your Income
For every $1 you earn from your side hustle, you keep
$0.79
Your side hustle is taxed at an effective 21.3% (federal income tax + self-employment tax + state tax)
Self-Employment Tax Breakdown
As a 1099 contractor, you pay both the employer and employee portions of Social Security and Medicare taxes — 15.3% total on 92.35% of your net self-employment income.
Social Security (12.4%)
$6,298
Medicare (2.9%)
$1,473
Deductible Half
-$3,886
You can deduct 50% of your SE tax from your adjusted gross income, reducing your federal income tax slightly.
Your Side Hustle Bottom Line
Quarterly Estimated Tax Payments
To avoid underpayment penalties, pay estimated taxes each quarter. Each payment is 1/4 of your total estimated tax liability (federal + SE + state).
Q1
$2,931
Due April 15
Q2
$2,931
Due June 15
Q3
$2,931
Due September 15
Q4
$2,931
Due January 15
Total annual estimated tax: $11,725
Want to tweak this scenario in the full stacking calculator (including W-2 wages)? Open it prefilled for Illinois. One warning about its Illinois line: the widget applies 4.95% to federal taxable income, which gives $1,227. The real IL-1040 charges the same rate on a much bigger number, so the figure to plan against is the $2,385above — the next section shows where the gap comes from.
What this result means in Illinois
The federal half comes first, and it is identical in every state. Self-employment tax applies to 92.35% of net earnings — $50,793 × 15.3% = $7,771, being $6,298 of Social Security and $1,473 of Medicare. Half of that, $3,886, comes back off your income. After the $16,100 standard deduction and the 20% QBI deduction (worth $10,223 here), federal income tax on what is left lands near $2,727.
Illinois is the third layer, and it is the simplest state tax on this site: one rate, no brackets, no local add-on. It is also the easiest to underestimate, because 4.95% of whatmatters more than the rate. Illinois begins at your federal AGI — $51,114here — subtracts the $2,925 exemption allowance, and charges 4.95% of the $48,189 that remains: $2,385. The federal brackets, by contrast, only ever see $24,791. Illinois taxes roughly 1.9× as much income as the IRS does at this profit.
All three together come to $12,884, an effective rate of 23.4% of gross. Notice what the Illinois share works out to: $2,385 on $55,000 of revenue is 4.34% of gross, not 4.95%. The headline rate is charged on base income, and base income is smaller than what a client pays you.
Figures assume no business expenses and no credits. Every deductible expense you track cuts all three layers at once, because it shrinks the Schedule C profit they all start from — run yours through the deduction estimator. Illinois credits sit outside this arithmetic: the state property tax credit, the K-12 education expense credit, and the Illinois earned income credit each reduce the state figure for filers who qualify.
How Illinois applies the flat 4.95%
There is no bracket table to read — Illinois has one rate, in force since July 1, 2017. What a freelancer actually needs is the base the rate is charged on, and that is four lines of the IL-1040.
| Step | Where it comes from | Amount |
|---|---|---|
| 1099 profit | Schedule C net profit | $55,000 |
| Less the deductible half of SE tax | Federal Schedule 1 — already out of AGI | −$3,886 |
| Illinois base income | IL-1040 Line 1 — your federal AGI | $51,114 |
| Less the 2026 exemption allowance | Schedule IL-E/EITC — one exemption | −$2,925 |
| Illinois net income | What the flat rate is charged on | $48,189 |
| × 4.95% | Illinois income tax | $2,385 |
The line that surprises people is the third one. Illinois stops at federal AGI, so nothing below that line follows your income to Springfield. The $16,100federal standard deduction does not exist in Illinois — the $2,925 exemption allowance is its whole replacement. Neither does the QBI deduction, which is worth $10,223 federally at this profit and nothing at all here, because Illinois has no equivalent subtraction on Schedule M.
That is the entire reason the $2,385 on this page runs above the $1,227 the site’s 50-state table shows. Both use 4.95% — for a flat-tax state the rate in that table is exactly right, which is unusual. They disagree only about the base, and for a flat state the base is the whole question.
Two things move the base in your favor. Business expenses cut Schedule C profit before any of this starts. And above-the-line deductions — a SEP-IRA or solo 401(k) contribution, or self-employed health insurance premiums — land above the AGI line, so unlike the standard and QBI deductions they follow you onto the IL-1040 and cut the Illinois bill too, at 4.95% each: $49.50 of Illinois tax saved per $1,000 contributed.
Your Illinois quarterly tax schedule
Two sets of estimated payments, one calendar. The IRS wants Form 1040-ES whenever you expect to owe $1,000 or more at filing. Illinois wants Form IL-1040-ES on the same $1,000trigger, measured against the Illinois bill alone after withholding and credits — which, on this page’s arithmetic, a freelancer crosses at roughly $24,900 of profit. Both want four equal installments on the same four dates.
| Quarter | Income earned | Due | Federal 1040-ES | Illinois IL-1040-ES |
|---|---|---|---|---|
| Q1 | Jan 1 – Mar 31 | April 15, 2026 | $2,625 | $596 |
| Q2 | Apr 1 – May 31 | June 15, 2026 | $2,625 | $596 |
| Q3 | Jun 1 – Aug 31 | September 15, 2026 | $2,625 | $596 |
| Q4 | Sep 1 – Dec 31 | January 15, 2027 | $2,625 | $596 |
| Year | $10,498 | $2,385 | ||
Illinois takes its share through MyTax Illinois or a paper IL-1040-ES voucher, and one payment covers the whole state liability — there is no separate city or transit voucher to track, because no Illinois municipality taxes income. Watch the calendar rather than the quarter names: Q2 covers only two months, and Q3 ends in August but isn’t due until mid-September, so a busy April can leave the June 15 payment short if you size it off a calendar quarter.
Illinois’ penalty safe harbors are the ones worth remembering, because they are simpler than the federal set: pay 90% of this year’s Illinois tax or 100% of last year’s, in four equal and timely installments, and no late-payment penalty applies — there is no higher percentage for high earners the way the federal 110% rule works. Farmers with two-thirds of gross income from farming, and people 65 or older living permanently in a nursing home, are excused from Illinois estimated payments entirely. The quarterly tax calculator sizes the federal checks from your own income, and the estimated tax payments guide covers what skipping one costs at the federal level.
Illinois 1099 taxes at other income levels
Same assumptions — filing single, no W-2 wages, no business expenses, no credits. The Illinois column runs the IL-1040 arithmetic above rather than a flat rate on federal taxable income.
| 1099 income | SE tax | Federal | Illinois | IL % of gross | Total | Set aside |
|---|---|---|---|---|---|---|
| $25,000 | $3,532 | $249 | $1,005 | 4.02% | $4,786 | 19% |
| $40,000 | $5,652 | $1,389 | $1,695 | 4.24% | $8,736 | 22% |
| $55,000 | $7,771 | $2,727 | $2,385 | 4.34% | $12,884 | 23% |
| $75,000 | $10,597 | $4,511 | $3,305 | 4.41% | $18,414 | 25% |
| $100,000 | $14,130 | $7,527 | $4,456 | 4.46% | $26,112 | 26% |
Read the two right-hand columns together and you can see exactly which layer is progressive. The Illinois share barely budges — from 4.02% to 4.46% across a fourfold change in income, creeping up only because the fixed $2,925 exemption matters less as income grows. The set-aside percentage climbs much faster, and all of that is federal brackets. Turn whichever figure is yours into a per-invoice habit with how much to set aside, or see what the same profit costs in Texas, where the Illinois column is zero.
The one break a flat rate hands Illinois freelancers
Illinois does not tax retirement income. Distributions from a qualified plan, an IRA, or a self-employed retirement plan are subtracted back out on IL-1040 Line 5, along with federally taxed Social Security. For someone with a SEP-IRA or solo 401(k), that makes the Illinois arithmetic unusually one-sided: the contribution is above the AGI line, so it cuts Illinois base income today at 4.95%, and Illinois never taxes the money on the way out.
On this page’s $55,000 of profit, net earnings of $51,114 support a SEP-IRA contribution of up to $10,223 — worth $506off the Illinois bill — or, with a solo 401(k)’s salary deferral stacked on the same employer contribution, up to $34,723, which would take $1,719 off it, about 72% of the whole $2,385. Few freelancers can spare that much of a $55,000profit — the point is the rate at which partial contributions work: every $1,000 in is $49.50 of Illinois tax saved on top of the federal saving, and none of it comes back later.
Health insurance premiums behave the same way, and the self-employed health insurance deduction is the other above-the-line item most freelancers already have. Business expenses beat both, because they come off before SE tax as well as before income tax.
Illinois 1099 Questions
How much tax does a 1099 contractor in Illinois pay on $55,000?
Filing single with no business expenses, about $7,771 of self-employment tax, roughly $2,727 of federal income tax, and about $2,385 of Illinois income tax — around $12,884 altogether, or 23% of gross. The Illinois piece is 4.95% of $48,189, which is your federal AGI of $51,114 less the $2,925 exemption allowance for 2026.
Does Illinois charge its own self-employment tax?
No. The 15.3% self-employment tax is federal — it funds Social Security and Medicare and is the same in Peoria as in Phoenix. Illinois taxes the same Schedule C profit through its personal income tax instead, at one flat rate, and that sits on top of the federal bill rather than replacing any part of it. Illinois does allow you the same relief the IRS does on the way in: the deductible half of your SE tax is already out of the federal AGI Illinois starts from.
Does Chicago have a city income tax on 1099 income?
No. No Illinois municipality levies an income tax, so unlike a freelancer in New York City there is no fourth layer to budget for — your Illinois income tax is the whole state-and-local income tax bill whether you work out of Chicago, Naperville, or Carbondale. Chicago does reach freelancers in other ways, most often through its personal property lease transaction tax, which covers rented equipment and some cloud software subscriptions. That is a tax on what you buy, not on what you earn, and it is deductible as a business expense.
Do Illinois freelancers have to make state estimated payments?
Yes, once the Illinois bill is big enough. Form IL-1040-ES is required if you expect to owe more than $1,000 of Illinois tax after withholding and credits, which a full-time freelancer clears at roughly $24,900 of profit. Illinois asks for four equal installments on the federal dates — April 15, June 15, September 15, and January 15 — and paying either 90% of this year's Illinois tax or 100% of last year's, in four timely installments, keeps you clear of the late-payment penalty.
Why is the Illinois tax on this page higher than the site's calculator shows?
Because the rate was never the hard part — the base is. The 50-state comparison table applies 4.95% to federal taxable income, which has already been cut by the $16,100 standard deduction and the 20% QBI deduction, giving $1,227 here. Illinois starts from federal AGI instead, and its only subtraction is the $2,925 exemption allowance — so it taxes $48,189 rather than $24,791, and the real bill is about $2,385. Set money aside against the figure on this page.
Does forming an LLC change what an Illinois 1099 contractor pays?
Not the income tax. A single-member LLC is a disregarded entity for both federal and Illinois purposes, so the profit still lands on your IL-1040 and still gets taxed at 4.95%. What changes is filing: Illinois charges a $75 annual report fee to the Secretary of State. Electing S corporation treatment — or taking on a second member and becoming a partnership — is the bigger change, because those entities owe Illinois' personal property replacement tax of 1.5% on Illinois net income — a tax a sole proprietor filing IL-1040 never touches — on top of the 4.95% you pay personally on what flows through.
Is Illinois' flat 4.95% going to become a graduated tax?
Not without a constitutional amendment. Article IX, Section 3(a) of the Illinois Constitution requires that "a tax on or measured by income shall be at a non-graduated rate," and the 2020 ballot measure to repeal that requirement was defeated, roughly 53% to 47%. The rate itself is ordinary statute, though, and it does move: it went from 3.75% to today's 4.95% effective July 1, 2017. Plan for the rate to change some year; don't plan for brackets.
How much is the Illinois exemption allowance, and can I lose it?
For 2026 it is $2,925 per exemption, worth $145 of tax each, with another $1,000 of allowance if you are 65 or older and again if you are legally blind. You do lose it at higher incomes: the exemption allowance, the Illinois property tax credit, and the K-12 education expense credit are all disallowed once federal AGI tops $250,000, or $500,000 filing jointly. Above that line Illinois is a clean 4.95% of base income with nothing taken off first.
Compare Other Scenarios
1099 Calculator for California
Nine brackets instead of one rate, and a 540-ES schedule that isn’t four equal payments
1099 Calculator for New York
Progressive state brackets plus a city income tax — the layer Illinois doesn’t have
Quarterly Tax Calculator
Size the four 1040-ES payments from your own income
All 50 State Tax Rates
Where Illinois’ 4.95% sits against every other state
Retirement Accounts for the Self-Employed
The deduction Illinois honors going in and never taxes coming out
How Much to Set Aside
Turning 23% into a per-invoice transfer