South Dakota Gas Tax

South Dakota taxes gasoline with a per-gallon excise of 28.0¢ and a 2¢ tank inspection fee. Motor fuel is not subject to the state sales tax, and the excise is not indexed to inflation or fuel prices.

The excise last changed on April 1, 2015, when legislation signed by Governor Dennis Daugaard raised it by 6¢, from 22¢ to 28¢. That was the first increase in 16 years. Proposals for automatic annual increases were debated at the time but were not part of the final law, so the rate has stayed at 28¢ since.

In the EIA’s July 2026 (revised August 2026) table, South Dakota’s state taxes and fees total 30.0¢ a gallon, tied for the 23rd-lowest of the 50 states and D.C., against a 51-jurisdiction average of 33.8¢. Because the tax is fixed in cents, it takes a larger share of the pump price when gasoline is cheap and a smaller share when prices rise. Current and historical prices are on the South Dakota gas prices page.

South Dakota and Iowa have exactly the same state gasoline tax in the EIA table: 30.0¢ a gallon in South Dakota, 30.0¢ in Iowa. That is why South Dakota is tied for the 23rd-lowest rather than holding a rank of its own.

Its other five neighbors split. Montana, at 33.8¢, and Minnesota and Nebraska, both at 32.7¢, charge more. North Dakota, at 23.0¢, and Wyoming, at 24.0¢, charge less, so a trip north from Aberdeen or west from Rapid City crosses into a lower-tax state, while one east from Sioux Falls into Minnesota crosses into a higher one. Of the six, only Montana is flagged by the EIA for local option fuel taxes, so its real figure can be higher than the one shown.

The state figure is 28.0¢ of excise plus a 2.0¢ tank inspection fee. The federal 18.4¢ brings the combined rate to 48.4¢, and South Dakota’s share of it is a little over three-fifths. The average across the 50 states and the District is 33.8¢, which puts South Dakota below the middle of the table on state tax even though its excise was raised as recently as 2015.

In the EIA's July 2026 table, South Dakota's 30.0¢ is 6.0¢ above Wyoming's 24.0¢ and 7.0¢ above North Dakota's 23.0¢. The other gaps run the opposite way: South Dakota is 2.7¢ (EIA table, July 2026) below Minnesota, 2.7¢ below Nebraska and 3.8¢ below Montana's 33.8¢. Iowa also shows 30.0¢ (EIA table, July 2026), a gap of 0.0¢. In all, 3 (EIA table, July 2026) of 6 bordering states have a higher state total, and Montana is the highest of them.

Alaska's 9.0¢ is the lowest state total in the EIA's July 2026 table and California's 73.6¢ is the highest. South Dakota's 30.0¢ (EIA table, July 2026) has 22 jurisdictions below it and 27 above it, which leaves it tied for 23rd-lowest.

In that July 2026 table, 93% of South Dakota's state total is excise, and the other 2.0¢ comes from other state taxes and fees. The federal tax is 18.4¢ (EIA table, July 2026), which brings the combined figure to 48.4¢, and the state's share of that combined figure is 62%. County and local taxes do not appear in the EIA's July 2026 figures for South Dakota, so the 30.0¢ covers state taxes of general application only.