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Haul Math

Connecticut IFTA Fuel Tax Rate, 3rd Quarter 2026

Connecticut's IFTA diesel rate for the 3rd quarter of 2026 is $0.4990 per gallon, up $0.0100 from Q2 2026.

Connecticut rate for Q3 2026

Special diesel, Q3 2026

$0.4990

per US gallon, up $0.0100 from Q2 2026

Diesel tax rate
$0.4990/gal
Surcharge
None listed
Quarter
Q3 2026, from Jul 1, 2026
Change vs last quarter
up $0.0100
Notes from the source

Matrix footnote #15 (CONNECTICUT): See Announcement 2024(1) Conversion Factors on Motor Vehicle Fuels Occurring In Gaseous Form for information about conversion factors for compressed natural gas and propane. See Announcement 2026(2) Motor Vehicle Fuels Tax Rate on Diesel Fuel Effective July 1, 2026.

Worked example: the Connecticut line of your IFTA return

Change the numbers to match your quarter. Prefilled with 10,000 total miles on 1,550 gallons, 1,200 of those miles in Connecticut, and 100 gallons bought there.

Example numbers are filled in. Tap "Calculate Connecticut IFTA" to see the Connecticut line of an IFTA return at the Q3 2026 rate.

Connecticut vs. its neighbors, Q3 2026

IFTA diesel rates for Connecticut and bordering jurisdictions, Q3 2026
JurisdictionDiesel + surchargevs. CT
Connecticut$0.4990—
Rhode Island$0.4000−$0.0990
New York$0.3805−$0.1185
Massachusetts$0.2400−$0.2590

On an IFTA return, a higher rate doesn't mean you pay more overall. Fuel you buy in a high-rate state earns a bigger credit. What matters is where you burn the fuel versus where you buy it.

Connecticut rate, last 4 quarters

Connecticut IFTA diesel rate by quarter
QuarterDieselSurchargeChange
Q4 2025$0.4890——
Q1 2026$0.4890—no change
Q2 2026$0.4890—no change
Q3 2026$0.4990—+$0.0100

Source: IFTA, Inc. Fuel Tax Rate Matrix, 3rd Quarter 2026 · Effective Jul 1, 2026 · Last verified Sep 28, 2026

IFTA, Inc. publishes the rates each member jurisdiction reports. Connecticut's tax agency is the final word on its rate.

Estimates for planning. Confirm with your tax pro or your base jurisdiction's IFTA office before filing.