Fuel and tax
Fuel Surcharge Calculator
Compares current diesel with a base diesel price, divides the difference by truck MPG, and applies the result to shipment miles. Surcharge per mile = (current diesel price - base diesel price) / MPG. It follows a cited U.S. Energy Information Administration source record captured 2026-08-12.
Calculate a transparent per-mile fuel surcharge with current EIA diesel or your contract inputs.
Enter operating details
Planning result
Enter valid values, then calculate.
- Detail
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Planning boundary: Results are planning estimates. Verify current source rules, operating records, contracts, and applicable requirements.
What this calculator returns
This fuel surcharge calculator applies a common per-mile model to a current or manually entered diesel price. It is for carriers, brokers, and shippers checking a transparent contract calculation. The EIA national diesel value is available as a convenience, while every economic input remains editable because index timing and contract formulas differ.
How this is calculated
The standard model subtracts the contract base diesel price from the selected current diesel price and divides the difference by the truck fuel economy. The result is a surcharge per mile, which is multiplied by shipment miles.
A zero floor is enabled by default so a price below the base does not create a negative surcharge. Users can disable that floor or enter a custom per-mile amount when the governing schedule uses a different table or calculation.
Surcharge per mile = (current diesel price - base diesel price) / MPG.
Variable definitions
- P
- Current diesel index or manually entered diesel price per gallon.
- B
- Base diesel price specified by the agreement.
- MPG
- Fuel economy assumption used by the surcharge model.
- M
- Shipment, route, or billed miles to which the surcharge applies.
Worked example
With current diesel at $5.257 per gallon, a $1.25 base, and 6.5 MPG, the price difference is $4.007. Dividing by 6.5 gives approximately $0.6165 per mile.
For 800 billed miles, the total from that model is about $493.23. A contract may instead use a weekly lag, regional EIA series, mileage bands, a lookup table, or a different MPG assumption.
How to interpret the result
The output explains every assumption so it can be compared with a rate confirmation or customer schedule. If the result differs, check the index date, region, base price, MPG, mileage basis, floor, and rounding.
The EIA shortcut does not make the formula official. It only fills the current-price field with a dated public observation.
Assumptions and limitations
There is no universal fuel-surcharge formula. Contract tables, floors, indexes, lags, and rounding can differ.
- There is no universal motor-carrier fuel surcharge formula.
- The national EIA price may not be the index or region named in a contract.
- The tool does not calculate a linehaul rate, fuel consumption, route mileage, or complete freight charge.
- Manual and custom values remain the user responsibility.
Rules and sources used
Frequently asked questions
What is the common fuel surcharge formula?
One common model is current diesel minus base diesel, divided by an assumed MPG, then multiplied by billed miles. Contracts can use different methods.
Where does the current diesel price come from?
The shortcut uses the latest stored EIA weekly US No. 2 on-highway diesel observation and shows its publication date.
Can a fuel surcharge be negative?
Some agreements use a floor while others can create a fuel discount. The zero-floor option makes that assumption explicit.