Montana gas tax
State fuel excise · tax year 2026 · federal tax excluded
On a 20-gallon fill
$6.60
Over 500 gallons
$165
Per gallon
33.0¢
state only
Rate rank
13
1 is the highest
What Montana charges at the pump
- Montana takes $6.60 in fuel tax from a twenty-gallon fill. Keep driving and the year's total reaches $165. On the rate behind those numbers the state comes 13 nationally. It is one of the few taxes you pay weekly and never think about once.
- Diesel gets no penalty in Montana. Twenty gallons of it carries $5.95 of state tax, against $6.60 on gasoline, and over a year the diesel total is $149. Most states charge diesel more. This one does not.
- The headline rate is not quite the whole story in Montana. There are separate charges on fuel too — inspection fees, environmental levies, that sort of thing — and they add $0.15 to a twenty-gallon fill on top of the main tax. Small on its own. Included in the price all the same.
- Fuel excise in Montana totals $6.60 per twenty-gallon purchase and $165 over five hundred gallons, a rate ranking 13 nationally. ⚠️ Excluding federal excise throughout. Because the charge is fixed in nominal cents rather than indexed to price, its real burden has declined steadily wherever a legislature has not revisited it — several states now index explicitly for that reason.
- No diesel premium applies in Montana: $5.95 per twenty gallons against gasoline's $6.60, or $149 annually at five hundred gallons. ⚠️ The majority of states levy diesel above gasoline to recover heavier road wear, so the parity here is a genuine cost advantage for freight operating in-state rather than a data artifact.
- Montana reports additional fuel levies apart from its principal excise — typically inspection, environmental or underground-storage charges — contributing $0.15 per twenty-gallon fill. ⚠️ These are reported separately by the state and are excluded from the headline rate on which the national rank is computed, so a like-for-like comparison against another state requires knowing whether that state folds equivalents into its main rate or reports them apart.
Your year of fuel tax
A $75,000 salary
| State fuel taxper gallon | 33¢ |
|---|---|
| Fuel tax, year | $206 |
| You must earn | $318 |
| Hours of work | 8.8 hr |
State excise only. Federal fuel tax and any local levy are not included.
Tax in a tank
A $75,000 salary
| State rate | 33¢ a gallon |
|---|---|
| Tank costs | $44.80 |
| Fifty tanks a year | $231.00 |
State excise only. The federal fuel tax and any local levy are on top of this.
Gasoline, diesel, and the charges reported separately
Per-gallon rates are shown as Montana publishes them, to a tenth of a cent. The money columns are what those rates come to on a 20-gallon fill and across 500 gallons. Federal tax is charged on top of all of it and is not included.
| Fuel | Per gallon | On a fill | Over a year |
|---|---|---|---|
| Gasoline | 33.0¢ | $6.60 | $165 |
| Diesel | 29.8¢ | $5.95 | $149 |
| Other state charges | 0.8¢ | $0.15 | — |
What this page cannot tell you
- ⚠️ Federal fuel tax is charged on top of all this and is not included above. It is the same everywhere in the country.
- The tank and the year here are round reference amounts, not a guess at your driving. Your own total scales directly with the gallons you actually buy in Montana.
- And some places add local fuel taxes of their own on top of the state's. Those are not counted here.
- ⚠️ Federal motor fuel excise applies in addition to every figure on this page and is deliberately excluded, being uniform nationally. Including it would raise each state's figure by the same amount and compress the differences this page exists to show.
- Quantities are reference points rather than estimates of consumption: liability is strictly proportional to gallons purchased, so any household's figure is this one scaled by its own volume. ⚠️ Fuel purchased outside Montana is taxed by the state where it is bought, which is why the figures describe purchases rather than mileage.
- Local option fuel taxes exist in a number of states and are excluded from these figures, which cover the state levy only. Where a county or city in Montana imposes its own charge, the true per-gallon burden at that address exceeds what this page reports.
Questions people ask
Why is there no tax line on my fuel receipt?
Because it was charged long before you got there. Fuel tax is levied per gallon on the way to the pump, so the price on the sign already contains it — nothing is added at the register, and the amount does not change with what the fuel happens to cost that week.
Is this a high-tax state for this?
Among the higher ones, yes — 13 of 51. The spread between states on this levy is wide enough that crossing a border can change the cost noticeably, which is exactly why cross-border buying is a live problem for revenue departments.
Is diesel taxed the same as gasoline?
It has a separate rate, below the gasoline one in this state. The two are set independently, generally on arguments about road damage from heavy freight.
Why does motor fuel excise not appear as a separate charge?
Motor fuel excise is levied per gallon at the distributor or terminal, not at retail, so it is embedded in the pump price and not separately stated. Because it is volumetric rather than ad valorem, liability per gallon is invariant to the retail price and its real value erodes with inflation absent legislative change.
Where does this state sit in the national distribution?
This state ranks 13 of 51, placing it in the upper third. Wide interstate dispersion in per-unit excise creates measurable cross-border purchasing effects, which several revenue departments model explicitly when forecasting receipts.
How does the diesel rate relate to the gasoline rate here?
Diesel is taxed at a rate set independently of gasoline and is lower in this state. The differential is generally justified by road-wear attribution to heavy vehicles rather than by fuel characteristics, and several states index the two grades differently.