Rocky Mountain region
MontanaGas prices
EIA doesn’t publish a weekly price for Montana on its own. This figure starts from the Rocky Mountain average of $4.417 for the week of October 5, 2026 and adjusts it for Montana’s fuel tax, which is 1.9¢ a gallon above the regional norm. How we estimate it.
Rocky Mountain prices this week
The regional averages Montana’s figures are drawn from, in dollars per gallon.
- Regular
- $4.417
- Down $0.069 on the week
- Midgrade
- $4.749
- Down $0.061 on the week
- Premium
- $5.097
- Down $0.079 on the week
- Diesel
- $6.267
- Down $0.140 on the week
The regional price is near its most expensive point of the past year: over the past 52 weeks it has run from $2.403 to $4.587, averaging $3.541. It has moved +2.4% over four weeks and +20.7% over thirteen.
How much of a gallon is tax
Montana charges 33.8¢ a gallon in state tax, the 19th highest of 51 (the 50 states and D.C.). With the federal tax that is 52.1¢, about 12% of the pump price.
| State excise tax | 33.00¢ |
|---|---|
| Other state taxes and fees | 0.75¢ |
| Federal excise tax | 18.40¢ |
| Total per gallon | 52.15¢ |
| On a 15-gallon fill | $7.82 |
| Over a year of typical driving | $250 |
From EIA’s notes for Montana: Petroleum Storage Tank Cleanup fee: $0.0075/gal on gasoline, diesel and fuel oil, aviation gasoline, and (non-military use) jet fuel.
Source: EIA federal and state motor fuel taxes, July 2026. A typical year assumes 480 gallons (about 12,000 miles at 25 mpg). Local sales taxes are not included.
Fuel tax in Montana and its neighbours
Across the line in North Dakota, state tax is 10.7¢ a gallon lower, which is $1.61 less tax on a 15-gallon fill.
| State | State tax | Versus MT | On a 15-gal tank |
|---|---|---|---|
| North Dakota | 23.0¢ | −10.7¢ | −$1.61 |
| Wyoming | 24.0¢ | −9.8¢ | −$1.46 |
| South Dakota | 30.0¢ | −3.8¢ | −$0.56 |
| Idaho | 33.0¢ | −0.8¢ | −$0.11 |
| Montana | 33.8¢ | — | — |
What driving in Montana costs
- A 15-gallon fill
- $66.53
- A year of typical driving
- $2,129
- Versus the national average
- $39 a year more
Planning a drive? The fuel cost calculator prices a trip at this week’s Montana figure, for your own car.
How we estimate the Montana price
The U.S. Energy Information Administration surveys retail gasoline prices every Monday, but it reports individual figures for only nine states. Montana is counted in the Rocky Mountain series, which averages it together with Colorado, Idaho, Utah and Wyoming.
Within one region, crude oil, refining and most delivery costs are shared. The biggest fixed difference from one state to the next is tax, which reaches the pump almost cent for cent. So we take the regional average and add the gap between Montana’s tax (33.8¢) and the average tax across the region’s states (31.9¢).
Local taxes, how busy the local market is and how far the state is from a refinery all move real prices too, so treat this as a guide to within a few cents, not a quote. Our methodology covers how every figure on the site is sourced.
Gas prices in Montana
- How much is gas in Montana right now?
- Regular gasoline in Montana is estimated at about $4.44 a gallon this week. That starts from the EIA's Rocky Mountain average of $4.417 and adjusts it for Montana's fuel tax, which is 1.9¢ a gallon above the average across the region's states. The national average is $4.354.
- How much is the gas tax in Montana?
- Montana charges 33.00¢ a gallon in state excise tax plus 0.75¢ in other per-gallon taxes and fees, 33.75¢ in all. That ranks 19 of 51 (the 50 states and D.C.), highest first. With the 18.4¢ federal tax, a gallon carries 52.1¢ of tax.
- Is gas cheaper in a state next to Montana?
- On tax alone, yes. North Dakota has the lowest fuel tax of Montana's neighbours at 23.0¢ a gallon, 10.7¢ less than Montana. On a 15-gallon fill that is $1.61 less tax. Station prices vary, so the saving at any one pump can be larger or smaller.
- Why is there no official weekly gas price for Montana?
- The EIA's weekly survey samples about 1,000 stations nationwide, enough for reliable regional averages and for nine large states, but not for every state on its own. Montana is counted in the Rocky Mountain series, which is updated every Monday and published on Tuesday.