Iowa
30¢/gal
State total · rank #27
- Excise
- 30¢/gal
- Other fees
- 0¢/gal
- + Federal
- 48.5¢/gal
- Annual state tax
- $144.00
Compare different states
Jan. 1 2026
Jan. 1 2026Iowa vs South Dakota Gas Tax
Iowa and South Dakota have the same 30¢/gal state gasoline tax. 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
Iowa and South Dakota are tied
Both total 30¢/gal state tax per gallon.
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
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
Iowa$144.00
South Dakota$144.00
Gap: $0.00
15,000 mi · 25 MPG
Iowa$180.00
South Dakota$180.00
Gap: $0.00
12,000 mi · 30 MPG
Iowa$120.00
South Dakota$120.00
Gap: $0.00
12,000 mi · 20 MPG
Iowa$180.00
South Dakota$180.00
Gap: $0.00
Key takeaways — Iowa vs South Dakota gas tax
- Iowa and South Dakota have the same 30¢/gal total state gasoline tax in 2026.
- Iowa ranks #27 nationally; South Dakota ranks #26 (#1 = highest state tax).
- Combined with federal 18.5¢/gal: Iowa 48.5¢/gal, South Dakota 48.5¢/gal.
- At 12,000 miles and 25 MPG, both cost about $144.00 in state gasoline tax.
- Iowa splits as 30¢/gal excise + 0¢/gal fees; South Dakota is 28¢/gal + 2¢/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 — Iowa vs South Dakota
State gasoline tax only (already in the pump price). Federal tax is the same in both states.
10-gallon fill-up
Iowa$3.00
South Dakota$3.00
Gap: $0.00
15-gallon fill-up
Iowa$4.50
South Dakota$4.50
Gap: $0.00
20-gallon fill-up
Iowa$6.00
South Dakota$6.00
Gap: $0.00
Annual state gas tax ladder
Same miles and MPG on both sides. Gap is absolute state-tax difference.
| Scenario | Iowa | South Dakota | Gap |
|---|---|---|---|
| Typical commute12,000 mi · 25 MPG | $144.00 | $144.00 | $0.00 |
| Higher mileage15,000 mi · 25 MPG | $180.00 | $180.00 | $0.00 |
| 30 MPG vehicle12,000 mi · 30 MPG | $120.00 | $120.00 | $0.00 |
| 20 MPG vehicle12,000 mi · 20 MPG | $180.00 | $180.00 | $0.00 |
| 20k miles · 25 MPG20,000 mi · 25 MPG | $240.00 | $240.00 | $0.00 |
How to read this page
Iowa vs South Dakota gas tax in 2026
Drivers comparing Iowa and South Dakota 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.
Iowa and South Dakota are tied at 30¢/gal state tax. Retail pump prices can still differ because of wholesale fuel costs, station margins, and local levies.
Open each state profile for fill-up examples and neighbor tables, or use the pair picker to swap states.
How Iowa and South Dakota build their gasoline tax
Iowa's 30¢/gal total is 30¢/gal excise and 0¢/gal other fees (rank #27). South Dakota's 30¢/gal is 28¢/gal excise and 2¢/gal fees (rank #26).
Federal tax does not change the winner: both states add 18.5¢/gal, so the combined gap equals the state gap (0¢/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: Iowa vs South Dakota
State fuel tax ≈ (miles ÷ MPG) × (¢/gal ÷ 100). At 12,000 miles and 25 MPG (480 gallons), Iowa is about $144.00 and South Dakota about $144.00 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 Iowa vs South Dakota 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 Iowa vs South Dakota comparison helps
Useful if…
- •Drivers choosing between living or working in Iowa vs South Dakota.
- •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.
Iowa vs South Dakota checklist
Before treating the rate gap as a relocation or fleet decision.
- 1Confirm Iowa 30¢/gal vs South Dakota 30¢/gal.
- 2Add federal 18.5¢/gal if you want total tax per gallon, not just the state gap.
- 3Plug in your miles and MPG to size the annual dollar difference.
- 4Check local fuel taxes and environmental program costs where you actually fill up.
- 5Open the Iowa and South Dakota profiles for neighbor and fill-up detail.
- 6Revisit after January 1 / July 1 if either state reindexes its excise.
Rates shown as 30¢/gal (IA) vs 30¢/gal (SD).
What the rate gap means
State gasoline taxes are tied; retail pump prices still differ with wholesale costs and local fees.
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.
Iowa vs South Dakota gas tax FAQs
Iowa and South Dakota have the same 30¢/gal total state gasoline tax. Iowa totals 30¢/gal and South Dakota totals 30¢/gal before the federal 18.5¢/gal.
At 12,000 miles and 25 MPG, both states cost about $144.00 in state gasoline tax.
Iowa: 48.5¢/gal combined. South Dakota: 48.5¢/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.
State gasoline taxes are tied; actual pump prices also reflect wholesale costs, refinery supply, and local fees.
State tax on 15 gallons is about $4.50 in both states before federal tax.
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.
State gasoline taxes are tied; both cost about $240.00 at 20,000 miles and 25 MPG.
Open the Iowa profile (/gas-tax-by-state/iowa) and South Dakota profile (/gas-tax-by-state/south-dakota) 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.
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Estimates use Tax Foundation statewide gasoline totals as of January 1, 2026. Local fuel taxes and diesel rates may differ.