Fuel Tax Calculator 2026

Enter gallons purchased, choose your state, and select gasoline or diesel. The calculator applies federal cents-per-gallon excise tax plus the selected state rate and converts the total into dollar amounts for your transaction.

The output separates federal tax, state tax, total fuel tax, and per-gallon breakdown so you can compare jurisdictions quickly. This is useful for drivers, fleets, and planners who need transparent cost components.

Rates shown are based on the cited source table. Some jurisdictions apply additional formulas or program fees, so this should be treated as a planning estimate, not a final compliance filing value.

Federal fuel tax baseline

Federal excise tax is the starting point for most U.S. fuel-tax calculations. For gasoline, the baseline is 18.4 cents per gallon. For diesel, it is 24.4 cents per gallon. Those federal rates are applied nationwide before state differences are added.

Because diesel’s federal rate is higher, heavy-duty and commercial operations often feel stronger tax sensitivity in diesel budgeting. Pairing per-gallon estimates with route and volume assumptions can materially improve fuel-cost forecasting.

Why state rates differ so much

States can use different transportation funding structures. Some rely heavily on fixed cents-per-gallon rates, while others blend fixed taxes with variable components or supplemental fees. That creates large interstate differences even when federal tax is the same.

For personal budgeting, state differences can influence recurring commute costs. For fleets, they can materially shift route economics, lane pricing, and regional operating strategy.

All 50 states fuel tax table

The table below lists state gasoline and diesel rates (cents per gallon) used in this calculator. Federal tax is added separately on top of these state values.

How to use this for better planning

If you are a household budgeter, use annual gallons consumed and your state profile to estimate yearly fuel-tax spend. If you are a business operator, combine this with mileage, MPG assumptions, and route state-mix to model quarterly and annual fuel-tax exposure.

Re-check source tables periodically because state rates can change. Keeping your model current prevents silent drift in cost assumptions over time.