Fuel Cost Calculator for Owner Operators

How do I calculate fuel cost for a trucking trip?

Trip fuel cost is total miles, loaded plus any deadhead, divided by your real miles per gallon, times the price you pay per gallon. Most Class 8 trucks average 5 to 8 miles per gallon, with newer, more aerodynamic trucks toward the top of that range and heavier loads or hilly terrain pulling it down. ATRI's 2026 report puts the average cost of running a truck at $2.336 a mile in 2025, or $1.854 without fuel. That makes fuel about 48 cents a mile, roughly a fifth of the cost. Even so, a small change in MPG or price moves your bottom line more than most other single factors. Add DEF too: guides put it at 2 to 3 percent of the diesel an on-road Class 8 truck burns, and Cummins says 3 to 5 percent.

1. Add up all the miles for the trip, including any deadhead to the pickup, not just the loaded miles.
2. Use your truck's actual average MPG, not the manufacturer's rated figure, since load and terrain change it.
3. Multiply total miles by the current diesel price, then divide by your MPG, to get total fuel cost.
4. If the trip crosses regions with different pump prices, estimate separately for each leg if the price gap is large enough to matter.
5. Add DEF at your own share of the diesel burned, starting from 3 percent.
6. To plan stops, enter each one with its mile marker and price. Buy only enough at an expensive stop to reach the next cheaper one, keep a reserve, and fill up where fuel is cheapest.
7. Compare fuel cost against the rate for the load to see what share of revenue fuel is taking.

These are typical ranges, not your truck's exact number. Load weight, terrain, idling, speed and driving style can swing real-world MPG well outside these bands, so track your own average from fill-ups rather than relying on a published range.

Last reviewed October 2026. Sources: ATRI: Operational Costs of Trucking; U.S. EIA: weekly retail on-highway diesel prices by region; Cummins: diesel exhaust fluid guide.