Montana Gas Tax Calculator
The Montana state gas tax is about 33.0¢/gallon. Calculate your total gas tax (state + federal) below.
What is the gas tax in Montana?
The Montana state gas tax is approximately 33.0 cents per gallon, which is above the rough national average of around 32 cents per gallon. On top of that, the federal gas tax adds a flat 18.4 cents per gallon everywhere in the US, so drivers in Montana pay a combined rate on the higher end nationally.
How much gas tax will I pay in Montana?
Use the calculator above to enter how many gallons you're purchasing and see the exact breakdown of Montana state tax, federal tax, and total tax on that fill-up.
This is an approximate combined state gas tax rate for estimation purposes — actual rates change periodically and may include additional local taxes not reflected here.
Frequently Asked Questions
What is the gas tax rate in Montana?
The Montana state gas tax is approximately 33.0 cents per gallon. Combined with the federal gas tax of 18.4 cents per gallon, use the calculator above to see the total tax on your fill-up.
Is Montana's gas tax above or below the national average?
Montana's gas tax of about 33.0 cents per gallon is above the rough national average of around 32 cents per gallon, putting Montana among the higher gas-tax states.
How much federal gas tax do I pay in Montana?
The federal gas tax is a flat 18.4 cents per gallon in every state, including Montana. This is added on top of Montana's own state gas tax of about 33.0 cents per gallon.
How much tax will I pay on 15 gallons of gas in Montana?
On 15 gallons in Montana, you'd pay roughly $4.95 in state gas tax and $2.76 in federal gas tax, for a total of about $7.71. Adjust the gallons in the calculator above for your own fill-up.
Why do gas prices vary within Montana?
Beyond the state gas tax, local factors like distribution costs, competition among stations, and proximity to refineries or terminals can cause gas prices to vary from city to city within Montana, even though the state and federal tax rate stays the same everywhere.
Does Montana's gas tax change often?
It depends on state law — some states adjust their gas tax rate periodically based on inflation or fuel price formulas, while others require new legislation to change the rate. Check Montana's department of transportation or revenue for the latest updates.
What is gas tax revenue used for in Montana?
Gas tax revenue in Montana, like most states, primarily funds road and bridge construction and maintenance, with some states also directing a portion toward public transit projects.