You are about to accept a load and need to know your fuel cost before you commit, not after you are already on the road losing money. Fuel is often one of the largest variable operating expenses for owner-operators and fleets, so getting this number right matters before you say yes to a rate.
We built this truck fuel calculator so you get an accurate diesel cost and cost per mile in seconds. Enter your trip distance, your truck MPG, and current diesel price. Select your equipment type and loaded status for a more accurate MPG estimate if you are not sure of your exact figure. The calculator shows your total fuel cost, gallons needed, and cost per mile instantly.
Written by the FuelConsumptionCalc Research Team
Formulas and figures on this page are cross-checked against standard trucking fuel calculation methods and industry MPG benchmarks.
Sources: EIA diesel price data, FMCSA motor carrier data, industry average MPG reports by equipment type.
See our full methodology page for how we verify every figure on this site.
Last Reviewed: July 2026
TRUCK FUEL CALCULATOR
Calculate semi truck diesel cost and cost per mile for any haul
Your Fuel Cost Breakdown
Enter your trip distance, truck MPG, and diesel price to calculate your total fuel cost, gallons needed, and cost per mile instantly. Select your equipment type for an MPG estimate if you do not know your exact figure.
Quick Answer
Truck Fuel Cost = (Distance / MPG) x Diesel Price Per Gallon
Example: 500 miles / 6.5 MPG x $3.80 = $292.31 for the haul
| Equipment Type | Typical Loaded MPG |
| Dry van | 800 miles |
| Reefer (unit running) | 1,200 miles |
| Flatbed | 2,000 miles |
| Hotshot | 2,400 miles |
| Box truck | 8.0 to 14.0 MPG |
How This Truck Fuel Calculator Works
This calculator turns your trip distance, truck MPG, and diesel price into a complete fuel cost breakdown. Enter your numbers and the calculator shows your total fuel cost, gallons needed, and cost per mile instantly, the figure that matters most when deciding whether a load rate actually makes sense.
If you are not sure of your exact MPG, select your equipment type and whether you are running loaded or empty, and the calculator uses an industry-average figure for that combination as a starting estimate. Your own logged MPG from actual fuel receipts will always be more accurate than any industry average, so use your real number whenever you have it.
Formula Used
Truck Fuel Cost = (Distance in Miles / MPG) x Diesel Price Per Gallon
Cost per mile uses a simpler direct formula:
Cost Per Mile = Diesel Price Per Gallon / MPG
Example Calculation
- Trip Distance: 500 miles
- Truck MPG: 6.5 MPG (loaded dry van)
- Diesel Price: $3.80 per gallon
- Step 1, Gallons Needed:
- 500 / 6.5 = 76.9 gallons
- Step 2, Total Fuel Cost:
- 76.9 x $3.80 = $292.31
- Step 3, Cost Per Mile:
- $3.80 / 6.5 = $0.585 per mile
This is the exact calculation the tool above runs the moment you click Calculate, using your own trip numbers instead of this example.
How to Use This Truck Fuel Calculator
Select your equipment type, enter your trip distance, your truck MPG,and your diesel price. Your total fuel cost, gallons needed, and cost per mile appear instantly.
Select Your Equipment Type
Choose your equipment type and loaded status to get a starting MPG estimate if you do not already know your exact figure. Dry van, reefer,flatbed, hotshot, and box truck each carry different typical MPG ranges, and loaded versus empty status changes the figure significantly within each category
.
Enter Your Trip Distance
Type in the miles for your haul. Use the loaded leg distance for an accurate fuel cost on a specific load, or your full round-trip distance including deadhead miles if you want your total cost for the complete trip.
Add Your Truck MPG
Enter your truck MPG if you know it from logged fuel receipts and odometer readings, since this is always more accurate than an industry average. Our MPG calculator can calculate your exact figure from a recent fill-up if you have not tracked it before.
Enter Your Diesel Price
Type in the current diesel price per gallon for your route. Diesel prices vary meaningfully by region and change frequently, so use the price at your planned fueling stops rather than a single national average for the most accurate trip cost.
Truck Fuel Cost Formula Explained
Truck fuel cost equals trip distance divided by MPG, multiplied by diesel price per gallon. Cost per mile divides diesel price directly by MPG. Both formulas are the same fuel cost math used across the trucking industry, just applied to commercial equipment instead of a passenger vehicle.
The Basic Formula
Gallons Needed = Distance in Miles / MPG Total Fuel Cost = Gallons Needed x Diesel Price Per Gallon Cost Per Mile = Diesel Price Per Gallon / MPG For multi-day trip planning beyond a single fuel cost figure, our trip fuel calculator adds fuel stop estimates based on your tank capacity.
Worked Example for a 500 Mile Haul
A loaded dry van runs 500 miles at 6.5 MPG. Diesel price is $3.80 per gallon.Gallons Needed = 500 / 6.5 = 76.9 gallons Total Fuel Cost = 76.9 x $3.80 = $292.31 Cost Per Mile = $3.80 / 6.5 = $0.585 per mile If the same truck ran empty (bobtail) at 8.5 MPG instead, the same 500 miles would cost $223.53, a difference of nearly $69 from loaded weight alone.
Loaded vs Empty MPG Makes a Big Difference
A loaded truck commonly sees 20 to 30 percent lower MPG than the same truck running empty, since the engine works harder to move the additional weight. Always use your loaded MPG when calculating cost for an actual haul, and your empty MPG when estimating deadhead or repositioning miles, since using the wrong figure for either leg meaningfully skews your total trip cost.
Average MPG by Equipment Type
Average MPG varies significantly by equipment type. Dry vans typically average 5.5 to 6.5 MPG loaded, reefers with the unit running average 4.5 to 5.5 MPG, flatbeds average 5.0 to 6.0 MPG, and hotshots average 8.0 to
12.0 MPG. Use your specific equipment category rather than a single trucking-wide average.
Dry Van
Loaded dry vans typically achieve 5.5 to 6.5 MPG on flat interstate driving. Running empty, the same truck often reaches 7.5 to 8.5 MPG, since the sealed trailer improves aerodynamics with less total weight to move.
Reefer
Reefer operations commonly experience lower fuel economy than comparable dry van operations, since refrigeration equipment consumes additional
fuel independent of the truck’s main engine. Newer, more efficient
reefer units can narrow this gap, so always use your own logged MPG for
a refrigerated load when you have it rather than a general benchmark.
Flatbed
Flatbeds average 5.0 to 6.0 MPG loaded, generally landing between dry van and reefer figures, though load shape and tarping can meaningfully
affect aerodynamic drag and therefore actual MPG on a given haul.
Hotshot and Box Truck
Hotshot rigs average 8.0 to 12.0 MPG, considerably more efficient than a full semi due to lower overall weight and smaller engine displacement. Box trucks in the 16 to 26-foot range average 8.0 to 14.0 MPG, with shorter routes and more frequent stops typically reducing real-world MPG below highway-only estimates.
Fuel Cost as Part of Your Total Operating Cost
Fuel is often one of the largest variable operating expenses for owner-operators and fleets, but it is only one part of your full cost per mile. Insurance, maintenance, tolls, permits, and driver wages all add to your total operating cost beyond fuel alone. Total operating cost per mile varies widely depending on equipment, insurance, maintenance, labor costs, and fuel prices, so there is no single figure that applies across every operation.
This calculator focuses specifically on fuel cost, since that is the variable that changes most with every load and route. Our cost per mile calculator helps you build out the fuller running cost picture beyond fuel when you need your true breakeven rate before accepting a load.
Fuel Surcharge and Truck Fuel Cost
Many trucking contracts include a fuel surcharge to offset changes in diesel prices. While this calculator estimates your direct fuel expense, fuel surcharges can partially recover those costs depending on the load agreement and current diesel market conditions.
Fuel surcharge structures vary by carrier and broker, with some indexed to a published national average diesel price and others negotiated directly into the rate. Comparing your calculated fuel cost against the surcharge offered on a load gives you a clearer picture of whether the rate actually covers your fuel exposure, rather than assuming the surcharge automatically matches your real cost.
What Affects Your Truck Fuel Cost
Four factors shape your truck fuel cost the most. Loaded weight has the biggest single impact, while terrain, speed, and idle time each compound on top of that baseline.
Loaded Weight
A fully loaded truck can see MPG drop 20 to 30 percent compared to running empty. Partial loads fall somewhere between the two extremes depending on actual freight weight relative to your truck’s maximum capacity.
Terrain and Route
Hilly or mountainous routes reduce MPG noticeably compared to flat interstate driving, since the engine works harder on sustained grades. Route planning that favors flatter interstates when load timing allows can meaningfully improve fuel economy on long hauls.
Speed and Driving Style
Every mph driven above 55 reduces fuel economy by roughly 0.1 MPG due to increased aerodynamic drag at higher speeds. Holding a steady 62 to 65 mph with cruise control engaged on the highway is a common industry-recommended sweet spot for balancing fuel economy against realistic schedule needs.
Idle Time
A truck idling overnight can burn close to a gallon of diesel per hour, which adds up fast across multi-day trips with overnight stops. Our idle fuel calculator helps you estimate exactly how much idle time is costing you across a typical week or month.
How to Reduce Your Truck Fuel Cost
Maintain proper tire pressure, since underinflated tires increase rolling resistance and can cost roughly 0.3 percent in fuel economy per PSI below the recommended level across all tires. Use cruise control on the highway to hold a steady speed rather than constantly accelerating and decelerating, and keep highway speeds in the 62 to 65 mph range when schedule and safety allow, since fuel economy drops measurably above that range.
Reduce unnecessary idle time, particularly overnight, using auxiliary power units or shore power where available instead of running the main engine purely for climate control or electronics.
Stay current on engine maintenance, including air filters, fuel injectors, and wheel alignment, since all of these affect drag and engine efficiency over time. Plan routes that minimize deadhead and empty miles, since every mile driven without freight still burns fuel without generating revenue.
Frequently Asked Questions
Related Calculators
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Idle Fuel CalculatorCalculate how much fuel and money idle time is costing you.
Fleet CalculatorCalculate total fuel costs across multiple vehicles for fleet managers and businesses.
Towing CalculatorEstimate the fuel cost impact of towing a trailer or load.
Monthly Fuel Cost CalculatorBudget your recurring fuel spend across multiple hauls per month.
Disclaimer
This calculator provides estimates only. Actual truck fuel costs vary based on equipment type, load weight, terrain, driving conditions, and regional diesel prices. See our full disclaimer page for more detail.