Tax Calculator

Paycheck Tax Calculator

All comparisons
South Dakota flagMontana flagJan. 1 2026

South Dakota vs Montana Gas Tax

South Dakota has the lower state tax by 3.75¢/gal. Compare excise, fees, combined federal + state rates, and annual tax at 12,000 miles and 25 MPG.

By Sammy S. · Founder · AuthorUpdated for 2026

Lower state gasoline tax

South Dakota is lower

3.75¢/gal lower per gallon—about $18.00 less state tax per year at 12,000 mi / 25 MPG.

Side-by-side gasoline tax scoreboard

South Dakota

30¢/gal

State total · rank #26

Excise
28¢/gal
Other fees
2¢/gal
+ Federal
48.5¢/gal
Annual state tax
$144.00
South Dakota profile →

Montana

33.75¢/gal

State total · rank #18

Excise
33¢/gal
Other fees
0.75¢/gal
+ Federal
52.25¢/gal
Annual state tax
$162.00
Montana profile →

Annual state gasoline tax comparison

State tax only at different mileage assumptions (25 MPG unless noted). Federal tax is identical in both states (18.5¢/gal).

12,000 mi · 25 MPG

South Dakota$144.00
Montana$162.00

Gap: $18.00

15,000 mi · 25 MPG

South Dakota$180.00
Montana$202.50

Gap: $22.50

12,000 mi · 30 MPG

South Dakota$120.00
Montana$135.00

Gap: $15.00

12,000 mi · 20 MPG

South Dakota$180.00
Montana$202.50

Gap: $22.50

Key takeaways — South Dakota vs Montana gas tax

  • South Dakota has the lower state gas tax by 3.75¢/gal (30¢/gal vs 33.75¢/gal).
  • South Dakota ranks #26 nationally; Montana ranks #18 (#1 = highest state tax).
  • Combined with federal 18.5¢/gal: South Dakota 48.5¢/gal, Montana 52.25¢/gal.
  • At 12,000 mi / 25 MPG, state tax is about $144.00 in South Dakota vs $162.00 in Montana—a gap of $18.00.
  • South Dakota splits as 28¢/gal excise + 2¢/gal fees; Montana is 33¢/gal + 0.75¢/gal.
  • Local fuel taxes and CA/OR/WA LCFS or cap-and-trade costs may not appear in these statewide totals.

Tax on a fill-up — South Dakota vs Montana

State gasoline tax only (already in the pump price). Federal tax is the same in both states.

10-gallon fill-up

South Dakota$3.00
Montana$3.38

Gap: $0.38

15-gallon fill-up

South Dakota$4.50
Montana$5.06

Gap: $0.56

20-gallon fill-up

South Dakota$6.00
Montana$6.75

Gap: $0.75

Annual state gas tax ladder

Same miles and MPG on both sides. Gap is absolute state-tax difference.

ScenarioSouth DakotaMontanaGap
Typical commute12,000 mi · 25 MPG$144.00$162.00$18.00
Higher mileage15,000 mi · 25 MPG$180.00$202.50$22.50
30 MPG vehicle12,000 mi · 30 MPG$120.00$135.00$15.00
20 MPG vehicle12,000 mi · 20 MPG$180.00$202.50$22.50
20k miles · 25 MPG20,000 mi · 25 MPG$240.00$270.00$30.00

How to read this page

South Dakota vs Montana gas tax in 2026

Drivers comparing South Dakota and Montana often ask which state takes more at the pump in fuel tax. This page lines up Tax Foundation 2026 statewide gasoline totals—excise plus other per-gallon fees—then adds the same federal 18.5¢/gal to both sides.

South Dakota wins on state gasoline tax by 3.75¢/gal per gallon. Over a typical 12,000-mile year at 25 MPG, that is about $18.00 less state fuel tax than Montana.

Open each state profile for fill-up examples and neighbor tables, or use the pair picker to swap states.

How South Dakota and Montana build their gasoline tax

South Dakota's 30¢/gal total is 28¢/gal excise and 2¢/gal other fees (rank #26). Montana's 33.75¢/gal is 33¢/gal excise and 0.75¢/gal fees (rank #18).

Federal tax does not change the winner: both states add 18.5¢/gal, so the combined gap equals the state gap (3.75¢/gal combined).

“Other fees” can include environmental, inspection, or storage charges. Percentage-based sales or gross-earnings taxes on fuel may still understate retail tax in some states.

Annual cost: South Dakota vs Montana

State fuel tax ≈ (miles ÷ MPG) × (¢/gal ÷ 100). At 12,000 miles and 25 MPG (480 gallons), South Dakota is about $144.00 and Montana about $162.00 in state tax alone.

Raise mileage or lower MPG and the dollar gap scales linearly. The ladder on this page shows 12k/15k miles and 20/30 MPG scenarios so you can match your commute.

Federal tax on those same gallons is about $88.80 in either state—useful for total tax budgeting, but irrelevant to which state wins the comparison.

When South Dakota vs Montana gas tax matters

Relocation, remote-work base choice, and long cross-border commutes are the main reasons to compare these two rates. A few cents per gallon compounds quickly for high-mileage drivers and fleets.

Pump price is still mostly crude, refining, and distribution. A lower gas tax state can post a higher street price if wholesale markets are tight.

For business mileage, the IRS standard mileage rate or actual expenses already embed fuel tax—there is no separate personal gas-tax deduction for commuting.

Who this South Dakota vs Montana comparison helps

Useful if…

  • •Drivers choosing between living or working in South Dakota vs Montana.
  • •Commuters who regularly fill up on either side of a state line.
  • •Fleet and rideshare operators budgeting per-mile fuel tax.
  • •Anyone estimating how much of the pump price is tax in each state.

Use official tools if…

  • •You need IFTA, dyed diesel, or refund compliance guidance.
  • •City or county fuel taxes dominate your usual stations.
  • •You primarily buy diesel or alternative fuels.
  • •You need a live retail price quote rather than statutory tax components.

South Dakota vs Montana checklist

Before treating the rate gap as a relocation or fleet decision.

  1. 1Confirm South Dakota 30¢/gal vs Montana 33.75¢/gal.
  2. 2Add federal 18.5¢/gal if you want total tax per gallon, not just the state gap.
  3. 3Plug in your miles and MPG to size the annual dollar difference.
  4. 4Check local fuel taxes and environmental program costs where you actually fill up.
  5. 5Open the South Dakota and Montana profiles for neighbor and fill-up detail.
  6. 6Revisit after January 1 / July 1 if either state reindexes its excise.

Rates shown as 30¢/gal (SD) vs 33.75¢/gal (MT).

What the rate gap means

At default driving, South Dakota saves about $18.00 per year in state gasoline tax versus Montana.

Limits of statewide totals

County and city fuel taxes, diesel schedules, and environmental program costs (especially CA, OR, WA) may not appear in these Tax Foundation gasoline totals.

South Dakota vs Montana gas tax FAQs

South Dakota has the lower state tax by 3.75¢/gal. South Dakota totals 30¢/gal and Montana totals 33.75¢/gal before the federal 18.5¢/gal.

At 12,000 miles and 25 MPG, South Dakota is about $144.00 and Montana about $162.00—a gap of $18.00 in state tax alone.

South Dakota: 48.5¢/gal combined. Montana: 52.25¢/gal combined. Federal gasoline tax is 18.5¢/gal nationwide.

No. County, city, and special-district fuel taxes are excluded. California, Oregon, and Washington table rates also omit cap-and-trade and LCFS-related costs that can appear at the pump.

This comparison uses Tax Foundation gasoline totals. Federal diesel tax is 24.5¢/gal (24.4¢ excise + 0.1¢ LUST). Several states apply different diesel excise or fee schedules.

South Dakota has the lower state gasoline tax, saving about $18.00 per year at 12,000 miles and 25 MPG—before federal tax and pump-price differences.

About $4.50 in South Dakota vs $5.06 in Montana for state tax—a $0.56 gap per fill-up.

No. Federal gasoline tax is 18.5¢/gal in both states, so the ranking by state total is the same as the ranking by combined federal + state tax.

South Dakota remains lower. At 20,000 miles and 25 MPG the state-tax gap is about $30.00.

Open the South Dakota profile (/gas-tax-by-state/south-dakota) and Montana profile (/gas-tax-by-state/montana) for excise/fee breakdowns, neighbor tables, and fill-up examples.

Compare another pair

Compare any two states

State gasoline tax rates with annual driving-cost estimates.

Estimates use Tax Foundation statewide gasoline totals as of January 1, 2026. Local fuel taxes and diesel rates may differ.