Illinois Self-Employment Tax Calculator (2026)
Federal self-employment tax, federal income tax and Illinois state income tax on 1099 income, plus how much to set aside for each estimated payment.
Federal 2026 and Illinois 2025 data checked against the official publications, last on 2026-09-05 Runs in your browser — nothing you type is sent anywhere, not even when you reload or share the link No sign-up Methodology and data status
- Total tax
- $17,975
- Effective rate
- 25.0%
- Set aside per quarter
- $4,494
- After-tax income
- $54,026
| Breakdown | |
|---|---|
| Net profit (income − expenses) | $72,000 |
| Self-employment tax | $10,173 |
| Social Security (12.4%) | $8,245 |
| Medicare (2.9%) | $1,928 |
| Federal income tax | $4,630 |
| Adjusted gross income | $66,913 |
| Standard deduction | −$16,100 |
| Qualified business income deduction (20%) | −$10,163 |
| Taxable income · marginal rate 12.0% | $40,651 |
| Illinois income tax | $3,171 |
| Total federal + state | $17,975 |
Amounts to set aside, not bills: federal $3,701 for each Form 1040-ES installment (Apr 15, Jun 15, Sep 15, Jan 15). Illinois: $793 per installment on its own schedule. For the safe-harbor amount and payments you have already made, use the quarterly calculator with these inputs. Illinois 2026 rates are not yet published; state figures use 2025 rates.
Illinois and self-employment income
Illinois has a flat 4.95% income tax with no standard deduction; instead each filer and dependent gets a $2,850 exemption (2025) — unless federal AGI exceeds $250,000 ($500,000 joint), at which point the entire allowance disappears. The state starts from federal AGI, so the deductible half of self-employment tax reduces Illinois income too.
Illinois rules used by this calculator (2025)
- Illinois applies a flat 4.95% rate for 2025.
- There is no standard deduction.
- Each filer gets a personal exemption that depends on income.
- The per-dependent deduction steps down as income rises.
- Illinois's earned income credit is 20% of the federal credit, refundable; the calculator applies it.
- A refundable 40% of the state earned income credit credit per return with a child under 12; the calculator applies it.
- Illinois starts from federal AGI, so the deductible half of self-employment tax reduces state income as well.
What an Illinois freelancer may still owe
- Illinois requires estimated payments (Form IL-1040-ES) when you expect to owe more than $1,000.
- Chicago and some other cities license home-based businesses; there is no municipal income tax in Illinois.
- Applied here: the Illinois earned income tax credit (20% of the federal credit, refundable) and the child tax credit of 40% of it for filers with a child under 12 (enter your children under 12 above).
What Illinois costs at three levels of profit (2026 federal, 2025 Illinois rates)
A single filer with no dependents and no other income, taking the standard deduction. The state column is Illinois's own tax after its deductions, exemptions and credits.
| Net profit | Federal (2026) | Illinois (2025 rates) | Total | Effective rate |
|---|---|---|---|---|
| $50,000 | $9,732 | $2,159 | $11,891 | 23.78% |
| $75,000 | $15,495 | $3,309 | $18,804 | 25.07% |
| $100,000 | $22,365 | $4,459 | $26,824 | 26.82% |
At $75,000 of profit, Illinois takes $3,309 — 17.6% of the total tax bill. Change any input in the calculator above to see your own figures.
How the federal part is worked out
Net profit is 1099 income less business expenses (Schedule C). Self-employment tax is 15.3% of 92.35% of that profit — 12.4% Social Security up to $184,500 of combined wages and earnings, 2.9% Medicare on all of it. Half of that tax, the $16,100 standard deduction ($32,200 joint) and the 20% qualified business income deduction come off before the 2026 brackets are applied; the child tax credit and the earned income credit then reduce what is left, and the refundable parts can offset self-employment tax. The methodology page sets out the full sequence and every rule the calculator leaves out, including how Illinois's figures are derived.
Quarterly estimated tax deadlines (2026)
If you expect to owe $1,000 or more of federal tax for the year, the IRS expects four estimated payments (Form 1040-ES). Illinois runs its own estimated-payment schedule with its own threshold (see above); the calculator shows the federal installment and the Illinois installment separately, and one combined amount to set aside each quarter.
The 2026 dates are April 15, 2026, June 15, 2026, September 15, 2026, January 15, 2027. The federal amount is split into four equal Form 1040-ES installments after any withholding you entered; paying 100% of last year's tax instead (110% above $150,000 of prior-year AGI) also avoids the penalty. The quarterly calculator works that out and subtracts what you have already paid, and the guide to the due dates explains the rule.
Common questions
Does Illinois tax self-employment income differently from wages?
For state income tax, net profit from self-employment is ordinary income like wages. The self-employment tax itself is federal only; Illinois does not add a state equivalent.
Is half of self-employment tax really deductible?
Yes, for federal tax. The employer-equivalent half is an adjustment to income on Schedule 1, which lowers your AGI and therefore your federal income tax. It does not reduce the self-employment tax itself.
Does an LLC change these numbers?
For federal income tax and self-employment tax, a single-member LLC taxed as a sole proprietorship follows exactly the calculation shown here. State and local obligations can still differ: an LLC may be a taxable entity for a state's franchise, gross-receipts or excise tax, and may owe registration or licence fees a sole proprietor does not — Illinois's are listed above. Electing S-corporation status changes the federal arithmetic too (salary plus distributions) and is outside this tool's scope.
What if I moved to Illinois during the year?
Income earned while you were a resident of another state is taxable there under that state's rules. This calculator assumes all income was earned as an Illinois resident.
Data sources and status
Federal figures for 2026: verified · last verified 2026-09-05 · the revenue procedures and forms they were read from, with every other data set
Illinois figures for 2025: verified · last verified 2026-09-08 · 2026 figures not yet published by the state
- Illinois Department of Revenue : 2025 Form IL-1040 instructions (rate 4.95%, line 1 = federal AGI)
- 2025 IL-1040 Line 10a Exemption Allowance Chart : $2,850 per person; no allowance when federal AGI exceeds $250,000 ($500,000 joint)
- Informational Bulletin FY 2026-15 (2026 exemption $2,925)
- 35 ILCS 5/201 (rate), 35 ILCS 5/204 (exemption)
- Illinois Department of Revenue : 2025 Form IL-1040 and Schedule IL-E/EIC instructions: line 29 Illinois earned income tax credit (20% of the federal credit as claimed, or recomputed on the expanded worksheet for ITIN filers and childless filers aged 18–24 or 65 and over; refundable) and line 30 Illinois child tax credit (40% of the Illinois EITC for a filer with a dependent qualifying child under 12, one per return, refundable — 35 ILCS 5/244, 40% for 2025 and later)
- Illinois Department of Revenue : 2025 Form IL-1040 and Schedule IL-E/EIC instructions: line 29 Illinois earned income tax credit (20% of the federal credit as claimed, or recomputed on the expanded worksheet for ITIN filers and childless filers aged 18–24 or 65 and over; refundable) and line 30 Illinois child tax credit (40% of the Illinois EITC for a filer with a dependent qualifying child under 12, one per return, refundable — 35 ILCS 5/244, 40% for 2025 and later; unchanged for 2026)
Illinois Department of Revenue · How figures are checked · Corrections log
Other states
Paying as you go? The quarterly estimated tax calculator applies the federal safe harbor and subtracts what you have already paid.