How Connecticut compares
Connecticut's diesel rate of $0.4990 is the 9th highest of the 57 jurisdictions that tax diesel through IFTA this quarter. The average among them is $0.3696; the lowest is Oklahoma at $0.1900 and the highest is California at $0.9790.
Example: 1,000 miles in Connecticut
A truck averaging 6.5 MPG that drives 1,000 miles in Connecticut burns 153.85 taxable gallons there. If none of its fuel was bought in Connecticut, it owes Connecticut $76.77 for the quarter (153.85 × $0.4990). Every tax-paid gallon bought in Connecticut reduces the base tax by $0.4990. Run your own numbers.
Connecticut rates by fuel type, 3rd quarter 2026
| Fuel | U.S. $ per gallon | CAD $ per litre |
|---|---|---|
| Diesel | $0.4990 | $0.1843 |
| Gasoline | $0.2500 | $0.0924 |
| Biodiesel | $0.4990 | $0.1843 |
| Gasohol | $0.2500 | $0.0924 |
| E-85 | $0.2500 | $0.0924 |
Propane, LNG, CNG, electricity and hydrogen are measured in different units from one jurisdiction to the next, so they are not listed here; see the official matrix.
Connecticut IFTA rate history
| Quarter | Diesel | Gasoline |
|---|---|---|
| 3Q 2026 | $0.4990 | $0.2500 |
| 2Q 2026 | $0.4890 | $0.2500 |
| 1Q 2026 | $0.4890 | $0.2500 |
| 4Q 2025 | $0.4890 | $0.2500 |
| 3Q 2025 | $0.4890 | $0.2500 |
| 2Q 2025 | $0.5240 | $0.2500 |
| 1Q 2025 | $0.5240 | $0.2500 |
When is the 3rd quarter 2026 return due?
IFTA returns for the 3rd quarter 2026 are due November 2, 2026. You file with your base jurisdiction, which pays Connecticut its share; miles in Connecticut go on that return whether or not you bought fuel there.
Rather not do this every quarter?
We reconcile your fuel receipts and mileage and prepare the quarterly IFTA return for you, next to your driver files and hours of service.
IFTA rates in other jurisdictions
United States
Canada
Rates in U.S. dollars per gallon (and Canadian dollars per litre) from the final IFTA, Inc. tax rate matrix. IFTAX is not affiliated with IFTA, Inc. or any government agency; confirm rates with your base jurisdiction before filing.