Last updated: May 2026 · Illinois IFTA rates current for Q1–Q4 2026
Illinois · 59.6¢/gal · #3 Highest in US

Illinois IFTA Calculator 2026 — Chicago Diesel Tax Rate & Filing

Illinois charges 59.6¢ per gallon in diesel taxes — 3rd highest nationally. If you run east-west freight through Chicago, calculate your IL IFTA liability and plan fuel stops in Missouri (19.0¢) to cut costs significantly.

Calculate Your Illinois IFTA Tax

Illinois IFTA Rates & Chicago Freight Overview 2026

Illinois's diesel tax rate of 59.6 cents per gallon is the third highest in the US. Illinois taxes include both a flat motor fuel tax and a sales tax component applied to diesel at the wholesale level. For Chicago-corridor freight, this adds meaningful cost on top of already-expensive tollway fees.

Chicago is the single most important freight junction in North America — over 50% of all US freight passes within 500 miles of Chicago. But for IFTA planning, Illinois's high rate means you should fuel up completely in Missouri (19.0¢/gal) before heading east. That's a 40.6¢/gal difference. On a 150-gallon fill, that's $61 in IFTA savings per fill.

Major Illinois Trucking Routes

I-80 (East-West, Chicago South): Iowa border east through Joliet, Chicago south suburbs to Indiana. The highest-volume commercial freight corridor in the US.
I-90/I-94 (Chicago Metro): Wisconsin border through Chicago to Indiana. Major urban congestion — plan for significant idle time and toll costs.
I-55 (Chicago to St. Louis): Chicago south through Springfield to the MO border. Fuel up on the Missouri side before heading north.
I-70 (East-West, Southern IL): St. Louis border east through Effingham to Indiana. Less congested east-west alternative to I-80.

Illinois IFTA — Frequently Asked Questions

What is the Illinois IFTA diesel tax rate in 2026?
Illinois's IFTA diesel tax rate for 2026 is 59.6 cents per gallon — the third highest in the US after Pennsylvania (74.1¢) and California (68.0¢). Illinois taxes diesel through both a motor fuel tax and a sales tax applied at the wholesale level.
Should I fuel up in Missouri before entering Illinois?
Yes — Missouri's diesel tax rate is only 19.0¢/gal, a 40.6¢ difference vs. Illinois. On a 150-gallon tank, fueling in Missouri instead of Illinois saves roughly $61 in IFTA liability. Fill up at truck stops in the St. Louis, MO area before heading east on I-64 or I-70.
How do tollway costs affect Illinois freight budgets?
The Illinois Tollway system (I-90, I-88, I-294, I-355) adds significant cost on top of the high IFTA rate. Commercial trucks pay per-axle tolls running $50–150+ on a Chicago-area run. I-80 and I-74 offer toll-free alternatives that many drivers prefer for both cost and congestion reasons.
How do I register for IFTA in Illinois?
Illinois IFTA registration is handled by the Illinois Department of Revenue (IDOR). Register and file quarterly at mytax.illinois.gov. Due dates: Q1 (Jan–Mar) April 30, Q2 (Apr–Jun) July 31, Q3 (Jul–Sep) October 31, Q4 (Oct–Dec) January 31.
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