How much does a Mechanical Engineer make in Illinois?

BLS reports a median annual wage of $99,730 for Mechanical Engineers in Illinois as of the latest OES release. That is the 50th-percentile figure — half earn more, half earn less. The 25th-percentile is $80,690 and the 75th-percentile is $124,490.

How many Mechanical Engineers does Illinois employ?

BLS OES counts 9,920 Mechanical Engineers employed in Illinois in the most recent release. Employment density relative to population determines whether wage tiers reflect a robust competitive market or a thinner labor pool.

Why is the BEA RPP for Illinois different from a single CPI number?

BEA splits regional price parity into three components — goods, services, and rents — reweighted to the BEA's national consumption basket. Illinois's overall index of 98.8 reflects rents 92.4, services 80.4, and goods 101.6.

How wide is the wage spread in Illinois?

P10 to P90 spans $67,200 to $143,500. That spread captures entry-level to top-quartile pay, including specialty differentials and metro-area variance within the state.

Is Illinois a 'real-wage arbitrage' state for Mechanical Engineers?

No — Illinois's RPP is close to the national 100 baseline, so nominal and real wages move roughly together. Neither an arbitrage nor a penalty state.

When does this data update?

BLS OES releases a new May reference set roughly each spring; we re-run the ETL pipeline within two weeks of release. BEA RPP refreshes annually. The last-synced timestamp at the top of this page reflects the most recent build.

Defense / aerospace vs auto vs HVAC mechanical engineer pay in Illinois?

BLS does not segment by industry. In {state}, defense and aerospace primes typically lead on base pay with strong total comp once retention/clearance bonuses layer in (often P75-P90 of the BLS band). Automotive and consumer products sit mid-band. HVAC / building-systems mechanical engineering pays below the BLS median for the first 5 years, then catches up via PE-track roles and design-build firm equity.

Illinois Mechanical Engineer Salary: BLS $100K Median, Real $101K (2026)

TL;DR

Mechanical Engineers in Illinois earn a BLS median of $99,730, with real take-home of $100,990 after BEA RPP adjustment.
Bottom quartile $80,690, top quartile $124,490. The P90 ($143,500) is roughly 2.1× the P10 ($67,200).
Cost adjustment is small — neither an arbitrage state nor a high-cost penalty.
State ranks #27 nationally on nominal wage, #35 on real (RPP-adjusted) wage.

Wage breakdown — Illinois

Percentile	Nominal (BLS)	Real (BEA RPP-adjusted)
P10 (entry tier)	$67,200	$68,049
P25 (lower quartile)	$80,690	$81,710
P50 (median)	$99,730	$100,990
P75 (upper quartile)	$124,490	$126,063
P90 (top tier)	$143,500	$145,314
Mean	$104,460	$105,780
Employment	9,920 Mechanical Engineers in Illinois

Cost of living — BEA Regional Price Parity

Component	Illinois index (US = 100)
All-items RPP	98.8
Goods	101.6
Services	80.4
Rents	92.4

Illinois's overall RPP (98.8) is close to the national 100 baseline; nominal and real wage move roughly together.

After-tax take-home — Illinois (2024 BLS · 2024 tax year, single filer)

Layer-by-layer take-home math at the BLS median

Layer	Amount	Note
Gross BLS P50 (Mechanical Engineer)	$99,730	nominal median
Federal income tax	−$13,188	13.2% effective; std deduction $15,750 applied
State income tax	−$4,937	4.95% flat (2026)
FICA (SS 6.2% + Medicare 1.45%)	−$7,629	SS capped at $183,600 wage base
Take-home (after-tax)	$73,976	74.2% of gross
Real take-home (RPP-adjusted)	$74,911	÷ (98.8 / 100) BEA cost-of-living

What the Illinois state-tax burden means for Mechanical Engineer take-home

Mid-band state-tax burden at 5.0% effective. Combined with federal and FICA, take-home is $73,976 (74.2% of gross). After the 98.8 RPP, real take-home is $74,911.

Computed from 2026 IRS federal brackets (Rev. Proc. 2025-32), 2026 state DOR brackets, and 2026 FICA rates. Single filer, standard deduction, no other adjustments. See methodology · tax for limitations (married filers, ITM/SALT itemizers, retirement deferrals, HSA, dependent credits, etc.).

National context

Across the United States, BLS reports a national median of $102,320 for Mechanical Engineers with mean pay of $110,080 and total employment of 286,760. Illinois sits at #27 on nominal pay and #35 on real (cost-adjusted) pay among the 51 states and DC. After cost adjustment, Illinois falls 8 positions — the cost premium eats into the headline wage.

Frequently asked questions

How much does a Mechanical Engineer make in Illinois?: BLS reports a median annual wage of $99,730 for Mechanical Engineers in Illinois as of the latest OES release. That is the 50th-percentile figure — half earn more, half earn less. The 25th-percentile is $80,690 and the 75th-percentile is $124,490.
How many Mechanical Engineers does Illinois employ?: BLS OES counts 9,920 Mechanical Engineers employed in Illinois in the most recent release. Employment density relative to population determines whether wage tiers reflect a robust competitive market or a thinner labor pool.
Why is the BEA RPP for Illinois different from a single CPI number?: BEA splits regional price parity into three components — goods, services, and rents — reweighted to the BEA's national consumption basket. Illinois's overall index of 98.8 reflects rents 92.4, services 80.4, and goods 101.6.
How wide is the wage spread in Illinois?: P10 to P90 spans $67,200 to $143,500. That spread captures entry-level to top-quartile pay, including specialty differentials and metro-area variance within the state.
Is Illinois a 'real-wage arbitrage' state for Mechanical Engineers?: No — Illinois's RPP is close to the national 100 baseline, so nominal and real wages move roughly together. Neither an arbitrage nor a penalty state.
When does this data update?: BLS OES releases a new May reference set roughly each spring; we re-run the ETL pipeline within two weeks of release. BEA RPP refreshes annually. The last-synced timestamp at the top of this page reflects the most recent build.
Defense / aerospace vs auto vs HVAC mechanical engineer pay in Illinois?: BLS does not segment by industry. In {state}, defense and aerospace primes typically lead on base pay with strong total comp once retention/clearance bonuses layer in (often P75-P90 of the BLS band). Automotive and consumer products sit mid-band. HVAC / building-systems mechanical engineering pays below the BLS median for the first 5 years, then catches up via PE-track roles and design-build firm equity.

Sources & methodology

U.S. Bureau of Labor Statistics — Occupational Employment and Wage Statistics (OES), SOC 17-2141, 2024 reference period.
U.S. Bureau of Economic Analysis — Regional Price Parities, 2023 vintage (all-items, goods, services, rents).
Real-wage figures = nominal BLS wage ÷ (state RPP / 100).
See the methodology page for full computation details and limitations.

By Marcus Liang · Founder & Editor · Last synced 2026-05-05.

Cross-comparison: see how Illinois Mechanical Engineer pay ranks against the other 254 state × occupation pages on the Real Wage Atlas → — four-way ranking by real wage, after-tax take-home, state-tax savings, and cost-of-living arbitrage.