What is the gas tax in Wisconsin?

Wisconsin charges a 30.9 cent per gallon motor-vehicle fuel excise plus a 2 cent petroleum inspection fee, for 32.9 cents per gallon in state tax. Adding the 18.4 cent federal excise brings the total to about 51.3 cents per gallon.

What is the petroleum inspection fee?

It is a 2 cent per gallon fee Wisconsin adds on top of the base fuel excise to fund petroleum inspection and cleanup programs. Drivers pay it at the pump along with the excise tax, so it is included in the per-gallon tax here.

How is the tax per mile calculated?

When you calculate by year, the tool divides your annual miles by your vehicle's MPG to find gallons burned, multiplies by the combined per-gallon tax, then divides the total tax by miles driven to show the tax cost per mile.

Is this the total price of gas?

No. This shows only the tax portion of fuel — the Wisconsin and federal per-gallon taxes. The pump price also includes the cost of the fuel itself, refining, distribution, and retailer margin, which vary daily and by station.

Does diesel have a different rate?

Slightly. Diesel is also subject to the Wisconsin fuel excise and inspection fee, but the federal diesel excise is 24.4 cents rather than 18.4 cents per gallon. This calculator uses gasoline rates.

Wisconsin Gas Tax Calculator

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Every gallon of gas you buy in Wisconsin carries both state and federal tax baked into the price. This calculator separates out the tax you actually pay, whether per fill-up or across a whole year of driving.

How it works

Gallons are turned into tax using fixed per-gallon rates:

Gallons (annual) = miles ÷ MPG
Wisconsin tax    = gallons × $0.329   (30.9¢ excise + 2¢ inspection)
Federal tax      = gallons × $0.184
Total tax        = gallons × $0.513

For a single fill-up you enter the tank size directly. For a year, the tool divides your mileage by your MPG to estimate the gallons burned, then applies the same per-gallon tax.

Example

A car with a 14 gallon tank pays about 7.18 dollars of fuel tax to fill up — 4.61 dollars to Wisconsin and 2.58 dollars to the federal government. Over a year of 12,000 miles at 28 MPG, that driver burns roughly 429 gallons and pays about 220 dollars in fuel tax, or 1.8 cents per mile.

Notes

These are the per-gallon tax amounts only — the pump price also reflects the cost of the fuel itself, which changes daily. Diesel uses a higher federal rate (24.4 cents) than the gasoline rate shown here. Wisconsin’s fuel excise has historically been adjusted by the legislature rather than indexed, so verify the current rate at revenue.wi.gov.