Fuel Surcharge Calculation Guide for Freight Dispatchers
The Short Answer
A fuel surcharge (FSC) is calculated using the weekly DOE national diesel average, a 'peg' price (the base fuel price already built into the line-haul rate), and a fuel mileage assumption. The standard formula is: (current diesel price − peg price) ÷ truck MPG = surcharge per mile. Dispatchers use FSC to keep a carrier's pay stable when diesel prices swing.
Diesel prices move constantly, and the fuel surcharge is the mechanism that keeps a carrier from absorbing every spike. Understanding how FSC is calculated lets a dispatcher make sure their carrier is paid fairly when prices climb.
The common fuel surcharge formula is: (current DOE diesel price − peg price) ÷ truck fuel mileage = surcharge per mile, then multiplied by loaded miles. The DOE national diesel average updates weekly, the peg price is the base fuel cost built into the line-haul rate, and MPG is typically assumed around 6. The result keeps carrier pay stable as diesel prices fluctuate.
The Three Inputs You Need
- DOE diesel price: the U.S. Energy Information Administration's national average, updated every Monday
- Peg price: the baseline diesel price already assumed in the line-haul rate (often around $1.20–$2.50 depending on the contract)
- Fuel mileage (MPG): the truck's assumed efficiency, commonly 6 MPG for a loaded tractor-trailer
The Formula, Step by Step
Subtract the peg price from the current DOE diesel price to find the price increase per gallon. Divide that by the truck's MPG to get the surcharge per mile. Multiply by the loaded miles to get the total fuel surcharge for the load. Example: ($4.20 DOE − $1.20 peg) ÷ 6 MPG = $0.50 per mile FSC.
| Step | Calculation | Result |
|---|---|---|
| 1. Price over peg | $4.20 − $1.20 | $3.00 / gallon |
| 2. Per-mile surcharge | $3.00 ÷ 6 MPG | $0.50 / mile |
| 3. Total on 800 miles | $0.50 × 800 | $400 FSC |
Why Dispatchers Should Track FSC
- Confirm whether the quoted rate is all-in or line-haul plus FSC
- Check the broker's fuel surcharge schedule against the current DOE price
- Make sure FSC is updating weekly, not stuck at an old rate
- Factor fuel cost into rate-per-mile decisions when accepting loads
All-In vs Line-Haul + FSC
Some brokers quote an 'all-in' rate that bundles fuel; others quote line-haul plus a separate fuel surcharge. Always clarify which you're getting — comparing an all-in rate to a line-haul-only rate without FSC is comparing apples to oranges.
Frequently Asked Questions
What is a fuel surcharge in trucking?
A fuel surcharge (FSC) is an adjustable fee added to the line-haul rate that rises and falls with diesel prices. It protects carriers from absorbing fuel price spikes and is usually tied to the weekly DOE national diesel average.
What MPG is used to calculate fuel surcharge?
Most fuel surcharge formulas assume around 6 miles per gallon for a loaded tractor-trailer. The lower the assumed MPG, the higher the surcharge per mile, so the assumption matters in negotiations.
What is the peg price in a fuel surcharge?
The peg price is the baseline diesel price already built into the line-haul rate. The fuel surcharge only kicks in for the amount the current DOE diesel price exceeds that peg, so a lower peg means the surcharge starts sooner.
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Michael Rivera
3PL freight broker with 10+ years experience and the lead instructor at Dispatcher Pro Academy.