practical guide
How to Build a Fuel Surcharge Table From the EIA Diesel Index
The EIA posts a national and regional on-highway diesel price every Monday. Here is how carriers turn that number into a per mile surcharge, pick a base peg, and set the MPG assumption that decides who eats a price spike.
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What the EIA On Highway Diesel Price Actually Measures
The Energy Information Administration (EIA) publishes the average retail price of diesel fuel sold at the pump across the country every Monday. The EIA surveys truck stops, major chains, and some independent retailers. Their posted price includes all taxes, fees, and charges that show up on a retail receipt.
This index is not the price a particular fleet pays at a specific stop. It is a broad average, intended to reflect what most over-the-road carriers pay per gallon when buying diesel across the United States. Some carriers negotiate discounts below this price, while others pay more in remote regions or during supply crunches.
Most fuel surcharges in the trucking industry are pegged to this EIA price, either at the national or regional level. Shippers, brokers, and carriers rely on this public number because it is updated regularly and accepted as a neutral source.
Keep reading: Leased On or Your Own Authority: The Cost Math for One Truck
Choosing a Base Peg: The Price Where the Surcharge Starts at Zero
The base peg is the diesel price assumed in your contract's base rate. When the EIA price is below this peg, no fuel surcharge is paid. Once the EIA index rises above the base peg, the surcharge formula kicks in to cover the increased cost.
Most contracts set a base peg that reflects average fuel prices at the time the contract was signed. If diesel cost $2.50 per gallon during negotiations, that often becomes the peg. A higher peg means no surcharge is paid until prices climb well above recent averages. A lower peg gives the carrier a surcharge sooner if prices rise.
It's essential to know your contract's base peg. Some brokers and shippers propose a peg that may be out of date compared to current market realities. Always check where your surcharge starts from, and push for a base peg that matches your true operating experience.
The Three Inputs: Peg, Index Price, and Assumed MPG
Every fuel surcharge calculation uses three main numbers: the base peg, the EIA diesel price, and an assumed miles-per-gallon (MPG) for the truck. The formula works like this: if the EIA price goes above the peg, the amount over the peg is divided by the assumed MPG. That result is the per mile surcharge.
- Base Peg: The contract's starting diesel price, usually in dollars and cents per gallon.
- EIA Diesel Price: The latest posted average, national or regional, updated each Monday.
- Assumed MPG: The fuel economy figure used to calculate how much diesel is needed for each mile. Most contracts use a round number, often 6.0 MPG, but this can vary.
The assumed MPG matters. If your contract uses 6 MPG but your trucks average 7 MPG, the surcharge will overcompensate for your real cost increases. If your trucks get 5.5 MPG but the formula uses 6 MPG, you pay the difference out of pocket. Your actual fleet average should guide what you negotiate for this number.
Keep reading: Seven Deadhead Mistakes That Cut Your Real Rate Per Mile
Building the Table in Six Cent Steps of Diesel Price
The most common fuel surcharge tables step up in six cent intervals. This mirrors the way many large shippers and brokers design their programs and matches templates used across the industry. The six cent step is easy to follow and keeps the surcharge responsive without changing every penny.
How to Build the Table
- List your base peg at the top. For example, $2.50 per gallon.
- Add rows in six cent increments: $2.56, $2.62, $2.68, and so on. Each row is a possible EIA price.
- For each EIA price, subtract the base peg. That is your "overage."
- Divide the overage by the contract's assumed MPG. This gives the per mile surcharge for that row.
For example, if the EIA price is $2.74, the base peg is $2.50, and the contract assumes 6 MPG: $2.74 minus $2.50 equals $0.24. Divide $0.24 by 6 MPG, and you get $0.04 per mile (rounded to the nearest cent).
Continue this process down the table. Each new six cent step adds one cent per mile to the surcharge, if the assumed MPG is 6.0. If the assumed MPG is higher, each step adds less per mile. If the assumed MPG is lower, each step adds more.
Table Example
| EIA Price | Over Peg | Divide by 6 MPG | Surcharge Per Mile |
|---|---|---|---|
| $2.50 | $0.00 | $0.00 ÷ 6 | $0.00 |
| $2.56 | $0.06 | $0.06 ÷ 6 | $0.01 |
| $2.62 | $0.12 | $0.12 ÷ 6 | $0.02 |
| $2.68 | $0.18 | $0.18 ÷ 6 | $0.03 |
| $2.74 | $0.24 | $0.24 ÷ 6 | $0.04 |
This table can be expanded as high as diesel prices may go. Most contracts cap the surcharge at a certain price, but you can build your table past that for planning and forecasting.
National Average Versus Regional Prices on a Western Lane
The EIA publishes both a national average and regional diesel prices. On a Western lane, fuel often costs more than the national average. For example, the West Coast, California, and Rocky Mountain regions have their own posted prices that can run much higher than the US average.
Carriers moving regular freight between, for example, Los Angeles and Seattle, may prefer to use the EIA West Coast or California price as their fuel surcharge index. This ties the surcharge more closely to actual fuel expenses in those high-cost markets.
Some contracts specify which regional price to use. If not, it is worth negotiating for a regional index that matches your lane. Using the national average can leave Western carriers short when diesel spikes locally. Regional surcharges are common on California outbound freight, produce, and seasonal lanes where fuel is a larger share of the total cost.
Keep in mind, though, that not all brokers or shippers will agree to a regional index. Many default to the national average for simplicity. If you run lanes with a big price gap between regions, track the difference and know how it affects your bottom line.
See how DeadheadMath handles this for trucking and logistics
Who the Surcharge Follows: Loaded Miles, All Miles, or Practical Miles
Every surcharge program defines which miles the surcharge applies to. This can make a significant difference in your total revenue from the surcharge. There are three common practices:
- Loaded Miles Only: The surcharge applies only to the paid, loaded miles from shipper to receiver. Deadhead miles are not included.
- All Dispatched Miles: Both loaded and empty miles assigned by the broker or shipper count. This is more generous to the carrier, especially if reloads are far apart.
- Practical Miles: Surcharge is paid on the miles shown by routing software, which may be less than actual hub miles if the route is optimized or rounded.
Most brokers pay the surcharge on loaded miles only. Some dedicated or long-term contracts include all dispatched miles. If your operation has high deadhead between loads, the choice of mileage base can make the difference between covering your fuel cost and losing out.
Always check your contract or rate confirmation to see which miles are eligible. If you are not sure, ask for clarification before booking the load. For some lanes, negotiating for all dispatched miles can add up to hundreds of dollars per month, especially in slow seasons or with irregular reloads.
Reading a Broker's Surcharge Off the Rate Confirmation
Most broker rate confirmations list the fuel surcharge as a separate line item, either as a flat per mile amount or as a total for the load. The confirmation may also state the EIA price used, the base peg, and the assumed MPG. In some cases, you may see only the final number with no details.
If there is any doubt, ask the broker for the exact formula and the EIA price they used. Some brokers lag the EIA price by a week, especially on loads booked Friday for a Monday pickup. Others update to the latest Monday price as soon as it posts. Knowing which price index and what date they are using can avoid confusion and disputes.
It is not uncommon to find mistakes in surcharge calculations, especially during rapid price swings. Always do the math yourself. If the number does not match your own table or calculation, point it out before accepting the load. Many brokers will correct obvious errors if caught before the load is dispatched.
Some confirmations list the mileage used to calculate the surcharge. Double-check this against the routing provided and your own GPS or routing software. If there is a short mileage listed, ask for a correction or appeal for practical miles if that is industry standard for the freight type.
Checking Your Surcharge Against What Fuel Actually Cost You
Once a trip settles, compare the fuel surcharge you received to your actual fuel expense per mile. Start with your total gallons bought for the trip, the total miles driven (loaded and empty), and the net fuel cost after any discounts or rebates.
Divide your total fuel spend by your total miles to get your actual fuel cost per mile. Next, compare your actual per mile cost to the base rate plus fuel surcharge received from the broker or shipper. In many cases, the surcharge will not cover the full difference unless diesel prices rise sharply or your contract uses a favorable MPG assumption.
If you buy fuel below the EIA index, you may come out ahead. If you pay more, or have a lower real-world MPG than the contract assumption, you may be left short. Track this on every trip to see patterns. Over time, this data can help you negotiate better surcharges or improve your fueling and routing choices.
Some carriers build spreadsheets or use software to automate this review. This makes it easier to see which lanes and customers pay fair surcharges, and which routes require more aggressive negotiation or smarter fueling strategies.
Tools that combine load settlement, fixed cost tracking, and per lane history can simplify surcharge audits. With a system that handles all these elements, owner operators and small carriers can spot where surcharge formulas help or hurt, and make better decisions on which loads to run and how to price them.
