Connecticut diesel tax rate is 49.2¢ per gallon for 2026. Calculate your quarterly IFTA fuel tax liability for Connecticut routes and compare to neighboring states.
Calculate Your Connecticut IFTA Tax
Gallons consumed in Connecticut→
Net taxable gallons→
Connecticut tax rate (2026)→49.2¢/gal
Estimated Connecticut IFTA→
Positive = amount owed to Connecticut; negative = credit on your quarterly return. This is one component of your full multi-state IFTA filing.
Connecticut IFTA Rates & Trucking Overview 2026
Connecticut's effective diesel rate of 49.2¢/gal makes it one of the most expensive fueling states in the US. The state is one of the smallest geographically — most drivers transit through Connecticut rather than fueling here. The I-95 corridor through Fairfield County is one of the most congested freight routes in the Northeast.
Major Connecticut Trucking Routes
I-95 (New Haven–Bridgeport–Stamford–NYC, major Northeast Corridor), I-91 (New Haven–Hartford–Springfield MA), I-84 (Danbury–Hartford–Providence RI), I-395 (Norwich–Massachusetts)
Most truckers on the I-95 Northeast Corridor time their fuel stops in New Jersey (42.1¢) or fill up before entering Connecticut if coming from Massachusetts (24.0¢) or New York (46.1¢). Connecticut's petroleum gross earnings tax structure means the effective rate fluctuates slightly with diesel prices, but remains consistently high. Hartford and New Haven are the primary freight markets.
Connecticut IFTA — Frequently Asked Questions
What is Connecticut's IFTA diesel tax rate in 2026?
Connecticut's effective IFTA diesel rate is approximately 49.2¢/gal in 2026 — one of the highest in the country. The rate includes the base excise tax plus a petroleum products gross earnings tax that varies with diesel prices.
Who administers IFTA for Connecticut-based carriers?
Connecticut IFTA is administered by the Department of Revenue Services (DRS). CT-based carriers file quarterly at the DRS online portal. Connecticut also has a Highway Use Tax (HUT) for vehicles over 26,000 lbs.
How do I minimize fuel costs running through Connecticut?
Top off in Massachusetts (24.0¢) before entering CT from the north on I-91 or I-84. From the south on I-95, fuel in New Jersey (42.1¢) before entering New York and CT. Connecticut is short enough that most drivers can transit without fueling.
Does Connecticut have a separate highway use tax?
Yes. Connecticut implemented a Highway Use Tax (HUT) for trucks over 26,000 lbs, charged per mile traveled on CT highways. This is separate from IFTA and adds to the effective cost of operating in Connecticut. Register at portal.ct.gov/HUT before operating.
Fueling tip: Fuel before entering CT whenever possible. Massachusetts at 24.0¢ is 25.2¢ cheaper per gallon — fill up before crossing the MA-CT border on I-90/I-84. New Jersey at 42.1¢ is also cheaper for I-95 southbound runs.