Q4 2026 IFTA diesel rate
Colorado IFTA fuel tax rate, Q4 2026
COColorado · diesel$0.3350/gal
Unchanged from Q3 2026.
Checked 2026-10-14 against tax.colorado.gov, Colorado's own published rate.
Calculate Colorado for Q4 2026Free. No account.
What you owe Colorado
IFTA apportions your fuel by miles. Divide total miles by total gallons for fleet MPG, turn your Colorado miles into taxable gallons, subtract the tax-paid gallons you bought in Colorado, and multiply by $0.3350.
Example: 1,000 miles in Colorado at 6.5 MPG is 153.85 taxable gallons. With 100 tax-paid gallons bought there, 53.85 × $0.3350 = $18.04 owed to Colorado.
This rate is for diesel, Q4 2026. You still file with your base jurisdiction; keep your trip records and receipts.