What does a Petroleum Engineers salary really buy you in Illinois?
Illinois is near the US average cost of livingData: BLS OEWS 2024 + BEA Regional Price Parities 2022 • Updated 2026-04-02
Illinois's Regional Price Parity (RPP) is 101.3, meaning prices are 1.3% higher the national average. A Petroleum Engineers earning $136,190 in Illinois has the equivalent purchasing power of $134,442 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) | $52,020 | $51,352 | $-667 |
| 25th Percentile (P25) | $92,000 | $90,819 | $-1,180 |
| Median (P50) | $136,190 | $134,442 | $-1,747 |
| 75th Percentile (P75) | $169,920 | $167,739 | $-2,180 |
| 90th Percentile (P90) | $227,700 | $224,777 | $-2,922 |
Illinois's cost of living is close to the national average, so $136,190 keeps most of its value at $134,442 in real terms. Location choice here is more about career opportunities than cost arbitrage.
Where does Petroleum Engineers salary stretch the furthest? Top 10 states ranked by COL-adjusted median salary.
Illinois ranks #11 out of 26 states for Petroleum Engineers after cost-of-living adjustment.
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How much do you actually take home? See Petroleum Engineers take-home pay in Illinois after taxes →
A Petroleum Engineers in Illinois earns a median salary of $136,190 per year. After adjusting for Illinois's cost of living (RPP=101.3), the real purchasing power is $134,442 — 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 Petroleum Engineers in Illinois: $136,190 x (100 / 101.3) = $134,442. This represents what the salary would be worth in a state with average living costs.