Truck Fuel Cost Calculator

Diesel prices today (September 22, 2026): Texas $5.965, California $8.439, Florida $6.258, Illinois $6.828, New York $6.504 and Georgia $6.344 per gallon. The cheapest diesel is in Texas ($5.965), Louisiana and Oklahoma; the most expensive is in California ($8.439), Washington and Hawaii. The EIA U.S. weekly average is $6.529.

Diesel in Texas averages $5.965 per gallon today (September 22, 2026), compared with the U.S. average of $6.529.

Today the cheapest diesel is in Texas at $5.965 a gallon, then Louisiana and Oklahoma. The most expensive is California at $8.439.

Divide the diesel price by your truck's miles per gallon. A loaded semi averaging about 6.3 mpg with diesel at $6.53 a gallon spends about $1.04 per mile on fuel. Heavier loads lower MPG: NACFE research puts it at about 0.5-0.6% more fuel for every 1,000 lbs, roughly 0.3-0.4 mpg per 10,000 lbs on a Class 8 truck.

A loaded Class 8 semi typically gets about 6 to 7 miles per gallon; empty, closer to 7 to 8 mpg. Speed, terrain, weather, aerodynamics and idling all change the number.

Roughly 0.14 to 0.17 gallons per mile for a loaded semi averaging 6 to 7 mpg. Multiply by the diesel price to get fuel cost per mile.

At about 6.3 mpg a semi burns roughly 159 gallons over 1,000 miles. At $6.53 a gallon that is about $1,038. Use the calculator above for your own truck, weight and state.

A 1-ton diesel pickup pulling a gooseneck typically gets about 12 to 14 mpg empty and about 9 to 11 mpg loaded, depending on cargo weight and trailer.

A 26-foot diesel box truck typically gets about 8 to 10 mpg, dropping toward 7 to 8 mpg near its maximum payload.

Yes. Heavier loads need more power, so MPG drops as weight goes up. The effect is larger on hotshots and box trucks, where cargo is a bigger share of total weight.

California has stricter fuel specifications, higher state taxes and fees, and a relatively isolated refining market, so its diesel price is usually the highest in the country.

State prices are AAA's daily state averages, refreshed every day. The U.S. average comes from the U.S. Energy Information Administration's weekly diesel survey, which is also used as a backup for any state without a daily price.

A loaded dry van or step deck averages about 6.0-6.3 mpg, a reefer about 6.0 mpg plus reefer unit fuel. At $6.53 a gallon, that is roughly $1.04-$1.09 of diesel per mile.

A 26 ft diesel box truck averages about 8.5-11 mpg depending on load, so fuel costs about $0.59-$0.77 per mile at $6.53 a gallon.

Cut deadhead miles, slow down (fuel use rises sharply above about 62 mph), reduce idling, keep tires properly inflated, and book loads that pay enough per mile to cover fuel. A dispatcher who plans lanes can help cut empty miles.