Q4 2026 IFTA diesel rate

Illinois IFTA fuel tax rate, Q4 2026

ILIllinois · diesel$0.7380/gal

Unchanged from Q3 2026.

Checked 2026-10-14 against tax.illinois.gov, Illinois's own published rate.

Calculate Illinois for Q4 2026Free. No account.

What you owe Illinois

IFTA apportions your fuel by miles. Divide total miles by total gallons for fleet MPG, turn your Illinois miles into taxable gallons, subtract the tax-paid gallons you bought in Illinois, and multiply by $0.7380.

Example: 1,000 miles in Illinois at 6.5 MPG is 153.85 taxable gallons. With 100 tax-paid gallons bought there, 53.85 × $0.7380 = $39.74 owed to Illinois.

This rate is for diesel, Q4 2026. You still file with your base jurisdiction; keep your trip records and receipts.