Last updated: 2025 BLS data · Page refreshed:
How much does a Hydrologists actually take home in Illinois?
5.0% flat rate — 24.9% effective total tax rateData: BLS OEWS 2025 + IRS/State Tax Brackets 2024 • Updated 2026-05-19
Detailed line-by-line tax calculation for a Hydrologists earning $83,720 in Illinois (single filer, standard deduction).
| Tax Component | Annual Amount | Effective Rate |
|---|---|---|
| Gross Salary (Median) | $83,720 | — |
| Federal Income Tax | -$10,259 | 12.3% |
| Illinois State Income Tax | -$4,144 | 5.0% |
| Social Security (OASDI) | -$5,190 | 6.2% |
| Medicare | -$1,213 | 1.5% |
| Total Taxes | -$20,808 | 24.9% |
| Take-Home Pay | $62,911 | 75.1% |
Take-home pay varies significantly across experience levels. Here is the after-tax breakdown for each salary percentile of Hydrologists in Illinois.
| Percentile | Gross Salary | Total Taxes | Take-Home Pay | Tax Rate |
|---|---|---|---|---|
| 10th Percentile (P10) | $59,070 | -$12,547 | $46,522 | 21.2% |
| 25th Percentile (P25) | $67,590 | -$15,227 | $52,362 | 22.5% |
| Median (P50) | $83,720 | -$20,808 | $62,911 | 24.9% |
| 75th Percentile (P75) | $110,110 | -$29,939 | $80,170 | 27.2% |
| 90th Percentile (P90) | $133,430 | -$38,373 | $95,056 | 28.8% |
After federal income tax ($10,259), state tax ($4,144), and FICA ($6,404), a Hydrologists in Illinois takes home $62,911 per year — or $5,242 per month. The effective tax rate of 24.9% is relatively low compared to the national range.
With an effective total rate of 24.9%, a Hydrologists in Illinois keeps $62,912 of $83,720 gross — roughly typical for U.S. middle-income earners once federal, FICA and state taxes are combined.
Illinois applies a flat state income tax — every dollar of wage income is taxed at the same rate. For this Hydrologists salary that contributes $4,144 to the 5.0% effective state-tax burden.
Federal tax on this Hydrologists salary is $10,259 (49%), but combined state ($4,144, 20%) + FICA ($6,405, 31%) make up the other 51% of the bill.
Moving this same Hydrologists salary to a zero-state-tax state would yield around $67,056 net — a gain of $4,144 (6.6%) per year versus Illinois.
Illinois sits near the bottom (#26 of 34) for Hydrologists after-tax earnings. Relocation, negotiation, or credential stacking typically show the clearest ROI in bottom-quartile states.
Translated into paycheck cadences, $62,912 net/year works out to $5,243/month or $2,420/bi-weekly for this Hydrologists in Illinois — the numbers that actually hit a checking account after every deduction.
Where does a Hydrologists keep the most of their paycheck? Top 10 states ranked by after-tax take-home pay.
Illinois ranks #26 out of 34 states for Hydrologists after-tax take-home pay.
A Hydrologists in Illinois earning a median salary of $83,720 will take home approximately $62,911 per year after federal income tax ($10,259), state income tax ($4,144), and FICA ($6,404). That is $5,242 per month or $2,419 per bi-weekly paycheck.
The effective total tax rate for a Hydrologists in Illinois is 24.9%, broken down as: federal income tax 12.3%, Illinois state tax 5.0%, and FICA (Social Security + Medicare) 7.6%. This assumes a single filer with the standard deduction for 2024.
Illinois has a 5.0% flat rate. On a Hydrologists's median salary of $83,720, the state income tax amounts to $4,144 per year, which is an effective state rate of 5.0%.
After all taxes, a Hydrologists in Illinois takes home approximately $5,242 per month, or about $30.25 per hour (based on a standard 2,080-hour work year). These figures assume a single filer, standard deduction, and no additional pre-tax deductions.
We start with the 2025 BLS median salary of $83,720 for Hydrologists in Illinois, then subtract: federal income tax using 2024 IRS brackets ($14,600 standard deduction), Illinois state income tax (5.0% flat rate), Social Security (6.2% up to $168,600), and Medicare (1.45%). The result — $62,911/yr — does not include local taxes, pre-tax deductions (401k, HSA), or tax credits.
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This estimate assumes a single filer using the 2024 standard deduction ($14,600), with W-2 employment income only. It does not account for: itemized deductions, tax credits (e.g. earned income credit, child tax credit), local/city taxes, pre-tax contributions (401k, HSA, FSA), self-employment tax, or additional income sources. Actual take-home pay may differ. Consult a tax professional for personalized advice.
Our Methodology · Data Sources · Salary: BLS OEWS · Tax: IRS + State DOR