Illinois 1099 Self-Employment Tax Calculator

Illinois has a flat 4.95% income tax rate. Estimate your self-employment tax, federal and Illinois state tax, effective rate, and quarterly payment amounts below.

Tax year 2026Last updated September 18, 2026

Total estimated tax

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Effective rate

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Take-home

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Set aside per $1

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Self-employment tax: —
Federal income tax: —
State income tax: —

Quarterly payment vouchers

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Estimates for tax year 2026, for informational purposes only — not tax advice. California's 2026 brackets haven't been published yet, so the most recent confirmed prior-year schedule is used as a placeholder; figures for New York, Ohio, Georgia, Virginia, Arizona, Massachusetts, Utah, Vermont, Maine, Mississippi, Missouri, Colorado, Connecticut, Delaware, Idaho, New Mexico, Oklahoma, and Oregon are drawn from secondary sources pending direct confirmation against the state's own published schedule. Consult a tax professional before filing.

Illinois self-employment tax, explained

Illinois' flat 4.95% rate applies equally regardless of income level, so it's straightforward to plan for as your freelance income scales up or down.

Self-employment (SE) tax is the same everywhere — 15.3% of 92.35% of your net profit, split between Social Security (12.4%, up to the annual wage base) and Medicare (2.9%, uncapped). What changes by state is the income tax layer on top: Illinois has a flat 4.95% income tax rate, applied to your taxable income after federal deductions. For filing status, Illinois's tax applies at the same flat rate to every filing status, since it's a single rate rather than brackets.

Illinois state tax at different income levels

Computed directly from Illinois's actual 2026 tax structure — a single filer with no other income and no expenses, at increasing levels of net 1099 profit:

Net profit	Illinois state tax	Effective state rate
$50,000	$1,203	2.4%
$100,000	$3,043	3.0%
$150,000	$4,883	3.3%
$250,000	$8,671	3.5%

Illinois worked example

A single freelancer in Illinois with $75,000 in net 1099 income and no other income:

Self-employment tax: $10,597
Federal income tax: $4,898
Illinois state income tax: $2,123
Total tax: $17,618 (about 23.5% effective rate)
Take-home: $57,382
Quarterly estimated payment: $3,964 per quarter

Try your own numbers in the calculator above — your actual income, expenses, and filing status will change these figures.

Frequently asked questions

What is the Illinois state income tax rate for 1099 income?

Illinois has a flat 4.95% income tax rate. Its tax applies at the same flat rate to every filing status, since it's a single rate rather than brackets. See the "Illinois self-employment tax, explained" section above for how it applies to your specific numbers.

How is self-employment tax calculated?

Self-employment tax is 15.3% of your net self-employment earnings (92.35% of net profit): 12.4% Social Security up to the annual wage base, plus 2.9% Medicare on all net earnings. If your combined income exceeds the Additional Medicare Tax threshold for your filing status, an extra 0.9% applies above that threshold.

What's the difference between self-employment tax and income tax?

Self-employment tax funds Social Security and Medicare — it's the self-employed equivalent of the payroll taxes an employer would otherwise split with you. Federal (and state) income tax is separate, calculated on your taxable income after deductions like the standard deduction and the QBI deduction.

Other Midwest states

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