Illinois S-Corp vs LLC Tax Calculator 2026
Illinois has a flat income tax rate of 5.0%, which applies to both LLC and S-Corp income equally. Use this calculator to compare your total tax as an LLC/sole proprietor vs an S-Corporation in Illinois.
Your Business Income
Gross 1099 income minus business expenses
Payroll, filing, legal (~$1,500–$3,000/yr)
S-Corp Salary Level
The IRS requires a "reasonable salary" — typically 40–60% of net income.
Side-by-Side Comparison — Illinois
Annual Tax Savings with S-Corp
$0
| LLC / Sole Prop | S-Corporation | |
|---|---|---|
| Net Income | $0 | $0 |
| Salary / SE Earnings | $0 | $0 |
| Distributions | N/A | $0 |
| SE / Payroll Tax | $0 | $0 |
| Federal Income Tax | $0 | $0 |
| Illinois State Tax | $0 | $0 |
| S-Corp Compliance Costs | $0 | $0 |
| Total Cost (Tax + Fees) | $0 | $0 |
| Take-Home Pay | $0 | $0 |
Breakeven Analysis
S-Corp vs LLC in Illinois
When comparing S-Corp vs LLC in Illinois, the key tax savings come from reduced self-employment/payroll taxes at the federal level. Illinois state income tax (illinois has a flat income tax rate of 5.0%, which applies to both llc and s-corp income equally.) applies equally to both entity types — it doesn't change based on whether you're an LLC or S-Corp, since both are pass-through entities for state tax purposes.
State note: Illinois has a flat income tax rate with a personal exemption.
How S-Corp Saves You Money
As an LLC/sole prop, you pay 15.3% self-employment tax on all net earnings (up to the $176,100 Social Security wage base for 2026). With an S-Corp, you only pay payroll taxes on your salary — distributions are exempt from payroll/SE tax. The lower your salary (within "reasonable" limits), the more you save. But the IRS requires salaries to be reasonable for your role, industry, and location.
Other States
No Income Tax States
Illinois Tax Quick Facts
- Income Tax
- Yes
- Tax Type
- flat
- Rate
- 4.95%
- SS Wage Base
- $176,100