If you are asking how do you calculate fuel surcharge for a truckload, the most common trucking formula is straightforward:
Fuel surcharge per mile = (Current diesel price − Base diesel price) ÷ Truck MPG
Then multiply the surcharge per mile by the billable miles for the load. For example, if diesel is $4.50 per gallon, your agreed base fuel price is $1.25, and the truck is priced at 6 MPG, the calculation is ($4.50 − $1.25) ÷ 6 = $0.5417 per mile. On a 1,000-mile shipment, the fuel surcharge would be about $541.67.
This is a common industry approach, but there is no single federally mandated fuel surcharge formula. The U.S. Energy Information Administration (EIA) explicitly states that it does not calculate, assess, or regulate diesel fuel surcharges. Shippers and transportation companies negotiate their own methods, although many use EIA’s weekly retail diesel price data as the index.
Fuel Surcharge Calculator Formula
A practical fuel surcharge calculator needs three inputs:
1. Current diesel price. Many carriers use the EIA weekly U.S. on-highway diesel average or a regional EIA average.
2. Base fuel price. This is the diesel price assumed to be included in the original linehaul rate. A commonly used example in truckload pricing is $1.25 per gallon, but your contract may use a different number.
3. Fuel economy in MPG. Use the MPG assumption stated in the contract or pricing schedule. If you are setting your own surcharge, use a realistic number that accounts for your operation rather than an optimistic dashboard figure.
The calculation is:
(Diesel price − Base price) ÷ MPG = Fuel surcharge per mile
To calculate the surcharge for the whole load:
Fuel surcharge per mile × Billable miles = Total fuel surcharge
Fuel Surcharge Calculation Example
Assume the following:
Current diesel price: $4.50/gallon
Base diesel price: $1.25/gallon
Fuel economy: 6 MPG
Billable distance: 1,000 miles
First, find the increase above the base:
$4.50 − $1.25 = $3.25 per gallon
Next, divide by the MPG assumption:
$3.25 ÷ 6 = $0.5417 per mile
Finally, multiply by the shipment miles:
$0.5417 × 1,000 = $541.67 fuel surcharge
If the base linehaul charge were $2,000, the invoice would become $2,541.67 before any other accessorials.
Where Does the Diesel Price Come From?
Many freight contracts use the EIA Gasoline and Diesel Fuel Update. EIA publishes weekly retail on-highway diesel prices for the United States and several regions. The important point is to define the index in advance. A national average and a regional average can produce different surcharge amounts.
EIA also makes clear in its fuel surcharge FAQ that companies establish their own surcharge methodology. That means the formula should be written into the rate agreement rather than assumed after the load is delivered.
Why Is a Base Fuel Price Used?
A linehaul rate normally assumes some amount of fuel expense. The base fuel price represents that built-in level. The surcharge is intended to compensate the carrier for diesel costs above that baseline, rather than charging the shipper for the entire cost of fuel twice.
For example, if your base linehaul was negotiated when diesel was assumed at $1.25 per gallon, the surcharge covers the portion above $1.25. If the current indexed price falls back to the base price, this formula produces a surcharge of zero.
How DAT Calculates Fuel Surcharge
DAT RateView uses the same basic structure: current EIA diesel price minus a $1.25 baseline, divided by an MPG assumption. DAT notes that the MPG should account for empty miles as well as loaded miles. That detail matters because a truck burns diesel on deadhead miles even when those miles are not producing freight revenue.
This is also why APR Logistics recommends evaluating rates on an all-mile basis. Read our guide to loaded RPM vs. all-mile RPM if you are pricing loads only from loaded miles.
Should You Use Actual MPG or a Standard MPG?
For a shipper-carrier contract, the safest approach is to use the MPG stated in the agreed fuel schedule. That keeps invoices predictable and auditable. If you are designing your own pricing model, however, your real operation should influence the MPG assumption.
A truck that averages 7 MPG has a lower incremental fuel cost per mile than one averaging 5.5 MPG. But fuel economy can also change with weight, speed, terrain, weather, equipment type, idling, and deadhead. The goal is not to choose the lowest MPG possible; it is to use a number that accurately represents the pricing agreement.
Do You Calculate Fuel Surcharge on Loaded Miles or All Miles?
This depends on the contract. A shipper may pay a surcharge only on the agreed loaded distance, while a carrier still incurs fuel expense on positioning and deadhead miles. If deadhead is significant, the carrier has to recover that cost somewhere—through the linehaul rate, an all-mile pricing model, or another negotiated structure.
For owner-operators, this is a critical distinction. A rate can look strong per loaded mile but weak after empty miles are included. Before accepting a load, calculate the total revenue against every mile your truck will move. Our true cost per mile guide provides the broader cost framework.
Fuel Surcharge vs. Fuel Cost Per Mile
These are not the same number.
Fuel cost per mile = Diesel price ÷ MPG. At $4.50 diesel and 6 MPG, actual fuel cost is $0.75 per mile.
Fuel surcharge per mile = (Diesel price − Base diesel price) ÷ MPG. Using the same $4.50 diesel, a $1.25 base, and 6 MPG, the surcharge is about $0.54 per mile.
The difference exists because the underlying linehaul rate is assumed to already cover fuel up to the base price.
How Often Should a Fuel Surcharge Change?
Weekly adjustments are common when the formula is indexed to EIA’s weekly diesel data. The rate agreement should state which published price applies, when the new surcharge becomes effective, whether there is a lag, and how rounding is handled.
A consistent schedule matters more than trying to time every movement in diesel prices. If the shipper and carrier use different weeks or different regional indexes, the same formula can still produce invoice disputes.
Percentage-Based Fuel Surcharges
Not every company charges fuel on a per-mile basis. Some parcel, LTL, delivery, and transportation companies apply a fuel surcharge as a percentage of the transportation charge. In those systems, the percentage is usually linked to a published fuel-price band or table.
For example, a carrier’s schedule might assign an 18% surcharge when its chosen diesel index falls within a specified price range. If the transportation charge is $1,500, an 18% surcharge would be $270. The exact percentage table is company-specific, so never substitute a generic percentage for the customer’s contractual schedule.
Common Fuel Surcharge Calculation Mistakes
Using pump price instead of the agreed index. Your local station price may not be the price specified in the contract.
Ignoring the base price. Dividing the entire diesel price by MPG calculates fuel cost per mile, not the incremental fuel surcharge.
Using unrealistic MPG. A fuel schedule built around an MPG figure that does not reflect the equipment can distort the surcharge.
Forgetting deadhead. Even when the customer pays the surcharge only on loaded miles, the carrier should price the load using the total movement required.
Mixing linehaul and all-in rates. Confirm whether the quoted rate already includes fuel before adding another surcharge.
Simple Fuel Surcharge Calculator You Can Use
Use this four-step calculation for a per-mile trucking surcharge:
Step 1: Find the current agreed diesel index.
Step 2: Subtract the contract’s base diesel price.
Step 3: Divide the difference by the agreed MPG.
Step 4: Multiply the result by the billable miles.
Example: ($4.25 − $1.25) ÷ 6.0 × 750 miles = $375 fuel surcharge.
Frequently Asked Questions
What is the formula for calculating fuel surcharge?
A common truckload formula is (current diesel price − base diesel price) ÷ MPG to get the surcharge per mile. Multiply that figure by the billable miles to calculate the load’s total fuel surcharge.
Who sets the fuel surcharge?
The shipper and transportation provider establish the surcharge through their pricing agreement. EIA publishes diesel price data but does not set or regulate fuel surcharges.
What diesel price should I use?
Use the price index specified in the contract. Many trucking agreements reference the EIA weekly national or regional on-highway diesel average.
Is fuel surcharge included in rate per mile?
Sometimes. Spot-market quotes are often discussed as all-in rates, while contract pricing may separate linehaul and fuel. Always confirm whether fuel is included before comparing two rates.
Bottom Line
If you need to calculate fuel surcharge, start with the agreed diesel index, subtract the base fuel price, divide by the agreed MPG, and multiply by the billable miles. The arithmetic is simple; the important part is making sure both parties use the same diesel index, base price, MPG, mileage definition, and update schedule.
For owner-operators, treat the surcharge as one part of the load economics—not as proof that the rate is profitable. Compare the all-in revenue against your true operating cost, deadhead, and total time before booking the load.