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 number that decides whether a load makes you money or burns it. ATRI's 2024 Operational Costs of Trucking report pegs fuel at $0.622/mi industry-wide — the largest line item ahead of driver wages ($0.795/mi all-in including benefits) and truck/trailer payments ($0.357/mi). The math is brutal in its simplicity: diesel price divided by MPG. Move either lever 5% and your bottom line shifts 5%. Owner-operators tracking this weekly catch dropping injectors, sticking brake calipers, and leaking fifth-wheel air lines weeks before the dashboard does.
The Formula
Variables
- Fuel Price — Pump price per gallon of #2 ULSD (ultra-low sulfur diesel)
- MPG — Actual measured MPG from fill-to-fill, not the dash readout
- Miles — Loaded plus deadhead miles for the trip
Worked Example
Owner-operator runs Harrisburg PA to Fontana CA round-trip in a 2022 Freightliner Cascadia, 5,560 total miles (2,780 each way) hauling dry van. Truck averages 7.1 MPG with the trailer skirts. 5,560 / 7.1 = 783 gallons. At the EIA national average of $3.79/gal (week of March 24, 2026), fuel runs $2,966. The eastbound load pays $5,200 (1.87/mi), westbound $4,950 (1.78/mi), totaling $10,150 gross. Fuel alone consumes 29.2% of revenue — and that's before $115 in DEF (2.5% of diesel volume at $4.40/gal), tolls of $387 across PA Turnpike and Indiana, and the $0.357/mi truck payment.
Practical Tips
- Maintain steer tires at 110-115 PSI cold and drives at 100-105 PSI per Michelin XZA3+ specs — every 10 PSI under-pressure on a single drive axle costs you 0.4 MPG. A digital gauge accurate to +/-1 PSI runs $30 at any TA Petro and pays for itself in two weeks.
- Roll at 62-63 mph in top gear on flat ground. NACFE Run on Less data showed average fleet MPG drops from 8.5 at 62 mph to 7.1 at 70 mph — a 16% efficiency loss for 13% more speed. The math never favors the higher pedal.
- Skip the Pilot/Flying J cash price and use the TCS or RTS fuel card cash discount network — typical savings run $0.30-$0.55/gallon at participating Loves and TA-Petros, no per-fill fees. Mudflap can stack additional discounts at independent stops the major cards skip.
- Idle time eats your monthly average. A Detroit DD15 at high idle burns 0.8 gal/hr. An eight-hour sleeper idle on a hot July night through Texas costs 6.4 gallons or roughly $24 — and contributes zero miles to your MPG denominator, dragging your monthly average down 0.2-0.3 MPG.
- DEF runs 2-3% of diesel volume. At 1,538 gallons/month diesel and $4.40/gal DEF, that's another $135-$203 monthly that doesn't show up in your fuel-card statements but absolutely shows up in your operating cost.
- Tracking method that actually works: log every fill in a spreadsheet with date, station, gallons, price, odometer. Calculate fill-to-fill MPG. If your 4-week rolling average drops 0.4+ MPG with no weather or load-weight explanation, schedule a Cascadia ECM scan — clogged DPF, bad MAF sensor, or sticking VGT actuator usually shows up before the engine light does.
Frequently Asked Questions
What is a good fuel cost per mile for a semi truck in 2026?
ATRI's 2024 benchmark is $0.622/mi fleet-wide. With EIA national diesel near $3.79/gal in early 2026, a Class 8 averaging 7.0 MPG runs $0.541/mi — better than fleet average. Anything above $0.65/mi at current pump prices points to MPG below 5.8, which is a maintenance flag, not a load-weight problem.
How many MPG does a typical semi truck get?
Industry average for a 2020+ aerodynamic Class 8 sleeper running interstates is 6.8-7.4 MPG loaded. NACFE's 2023 Run on Less Electric demo cohort averaged 8.0 MPG on diesel reference trucks. Older 2010-2015 trucks without skirts and tails run 5.8-6.5 MPG. Heavy haul or local stop-and-go drops another 1-1.5 MPG.
Does load weight really change fuel cost that much?
Yes — about 0.1 MPG lost per 5,000 lbs above empty trailer weight. Running 80,000 lbs GVW vs 50,000 lbs costs you roughly 0.6 MPG, which on a 2,500-mile run at $3.85/gal moves your fuel cost from $1,375 (7.0 MPG) to $1,503 (6.4 MPG). That's $128 gone before you account for grade or wind.
Why does my fuel cost per mile differ from what my dispatcher reports?
Dispatchers usually use a fleet-assumed MPG (often 6.5) and the contracted base fuel price, not your actual numbers. If you average 6.9 MPG and they bill at 6.5 MPG, the surcharge formula systematically underpays you about $0.04/mi at $4.00/gal diesel. Run your own number and benchmark against the dispatch report monthly.
Should I include DEF in my cost-per-mile?
Yes. DEF consumption is 2-3% of diesel volume in modern SCR-equipped trucks (post-2010 EPA). At $4.40/gal jug or $3.50/gal pump DEF and 7.0 MPG, you're adding $0.013-$0.019/mi. Small individually, but on 120,000 annual miles that's $1,560-$2,280 the dispatcher's math doesn't cover.
How do I cut my fuel cost per mile this month?
Three highest-impact moves in order: drop cruise from 68 to 63 (saves ~6%), check tire pressures cold every Sunday before the week starts (saves ~2-4% if any are low), and switch evening idle to bunk heater on diesel-fired Espar/Webasto units (saves ~$15/night vs main-engine idle). Combined, that's $0.04-$0.06/mi recoverable on most fleets.