Fuel Cost Per Mile
Calculate your fuel cost per mile and total fuel expense for any trip based on fuel price and truck MPG.
Results
Visualization
How It Works
Fuel cost per mile is the single most important operating metric for truck drivers and owner-operators. It directly impacts profitability on every load and helps you decide which freight to accept or reject. Tracking this number weekly helps identify maintenance issues and driving habits that waste fuel.
The Formula
Variables
- Fuel Price — Current price per gallon of diesel fuel
- MPG — Your truck's fuel efficiency in miles per gallon
- Miles — Total trip distance in miles
Worked Example
If diesel costs $3.85 per gallon and your truck gets 6.5 MPG, your fuel cost per mile is $3.85 / 6.5 = $0.592. For a 1,000-mile trip, you would need about 153.8 gallons, costing $592.31 in fuel alone. This means on a load paying $2.50 per mile, fuel alone eats about 24% of your gross revenue.
Practical Tips
- Keep your tires properly inflated — underinflated tires can reduce MPG by 0.3-0.5 MPG. Use a calibrated tire gauge rather than relying on visual inspection, as radial tires can look properly inflated even when significantly underinflated.
- Maintain a steady speed of 62-65 mph for optimal fuel efficiency on most Class 8 trucks. Aerodynamic devices like side skirts and trailer tails can improve highway fuel efficiency by 3-7%, complementing speed discipline for maximum savings.
- Use cruise control on flat highways to avoid unnecessary acceleration and fuel waste. Every MPH over 65 reduces fuel efficiency by approximately 0.1 MPG for most Class 8 trucks, making speed management one of the most controllable fuel cost factors.
- Track your fuel cost per mile weekly to spot trends and catch engine problems early. Research current pricing and specifications from multiple sources before committing, as market conditions and product offerings change frequently.
- Fill up at truck stops along your route using fuel discount apps like GasBuddy or Mudflap. Compare the net savings after any card fees or requirements, as some programs require minimum purchases or charge annual fees that offset the per-gallon discount.
Frequently Asked Questions
What is a good fuel cost per mile for a semi truck?
At current diesel prices around $3.85/gallon, a good fuel cost per mile is $0.50-$0.65. This assumes 6-7 MPG, which is typical for a well-maintained Class 8 truck.
How many MPG does a typical semi truck get?
Most semi trucks get between 5.5 and 7.5 MPG depending on load weight, terrain, speed, and aerodynamics. Newer trucks with aerodynamic packages can achieve 7-8 MPG.
Does load weight affect fuel cost per mile?
Yes, significantly. A fully loaded truck at 80,000 lbs GVW typically gets 1-2 MPG less than running empty or with a light load. Always factor in load weight when estimating fuel costs.
How can I reduce my fuel cost per mile?
Top strategies include reducing speed (every 1 mph over 65 costs about 0.1 MPG), maintaining proper tire pressure, using fuel discount programs, and avoiding excessive idling.
Should I include DEF fluid in my fuel cost calculation?
DEF typically costs about $0.01-$0.02 per mile. While small compared to diesel, owner-operators should include it for accurate cost tracking. DEF usage is roughly 2-3% of diesel consumption.