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What does a Data Scientists salary really buy you in Illinois?
Illinois is near the US average cost of livingData: BLS OEWS 2025 + BEA Regional Price Parities 2022 • Updated 2026-05-19
Illinois's Regional Price Parity (RPP) is 101.3, meaning prices are 1.3% higher the national average. A Data Scientists earning $106,560 in Illinois has the equivalent purchasing power of $105,192 in an average-cost US state.
Every dollar goes further in low-cost states. Here is how each salary percentile compares after adjusting for Illinois's cost of living.
| Percentile | Nominal Salary | COL-Adjusted | Difference |
|---|---|---|---|
| 10th Percentile (P10) | $68,810 | $67,926 | $-883 |
| 25th Percentile (P25) | $84,610 | $83,524 | $-1,085 |
| Median (P50) | $106,560 | $105,192 | $-1,367 |
| 75th Percentile (P75) | $137,290 | $135,528 | $-1,761 |
| 90th Percentile (P90) | $168,880 | $166,712 | $-2,167 |
Illinois's cost of living is close to the national average, so $106,560 keeps most of its value at $105,192 in real terms. Location choice here is more about career opportunities than cost arbitrage.
With an RPP of 101.3, Illinois is within a few percent of the national cost-of-living baseline. Salary adjustment for Data Scientists is therefore minor — what you earn is close to what you'd keep in real purchasing power.
After adjusting for Illinois's cost of living, $106,560 nominal nets out to $105,192 in real purchasing power — a small 1.3% loss. The state's cost profile is close enough to average that COL alone shouldn't drive location decisions for this Data Scientists.
Illinois's rank of #34 of 49 states means real purchasing power for Data Scientists trails the national half-way line.
Where does Data Scientists salary stretch the furthest? Top 10 states ranked by COL-adjusted median salary.
Illinois ranks #34 out of 49 states for Data Scientists after cost-of-living adjustment.
How much do you actually take home? See Data Scientists take-home pay in Illinois after taxes →
A Data Scientists in Illinois earns a median salary of $106,560 per year. After adjusting for Illinois's cost of living (RPP=101.3), the real purchasing power is $105,192 — a -1.3% difference.
Illinois's cost of living is 1.3% higher than the national average according to the BEA Regional Price Parities (2022). The RPP index for Illinois is 101.3 (US average = 100).
Regional Price Parities (RPPs) are price indexes published by the U.S. Bureau of Economic Analysis (BEA) that measure differences in price levels across states. They are expressed as a percentage of the national average (US = 100). Higher RPP means higher cost of living.
The adjusted salary is calculated as: Nominal Salary x (100 / RPP). For a Data Scientists in Illinois: $106,560 x (100 / 101.3) = $105,192. This represents what the salary would be worth in a state with average living costs.
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