Set the fuel terms before you calculate a load. The agreement should name the diesel price built into the base rate, the benchmark series and week, the MPG assumption, and the miles that qualify. For a per-mile surcharge, subtract the baseline price from the benchmark, divide by MPG, and multiply by eligible miles. Put that rule in the rate confirmation before invoicing.
The fuel surcharge calculator handles the arithmetic once you enter the agreed terms. The U.S. Energy Information Administration (EIA) publishes diesel prices. Shippers and transportation companies choose their own surcharge method; EIA does not set or endorse one.
Set the terms before calculating
| Term | Decision to record |
|---|---|
| Base rate and baseline | What fuel price per gallon does the base freight rate assume? Is fuel already included in an all-in rate? |
| Benchmark | Which exact price series applies, such as EIA U.S. on-highway diesel or a named EIA region? |
| Reference date | Which published week applies to this load, and when does a new week take effect? |
| Fuel economy | What MPG will the calculation use? |
| Eligible miles | Loaded route miles only, or specified empty miles too? Which mileage source controls? |
| Adjustment rules | Is the surcharge floored at zero, or can a price below baseline produce a credit? Are there caps, minimums, or rounding rules? |
EIA’s Gasoline and Diesel Fuel Update shows national and regional on-highway diesel prices by dated week. Use the series named in the agreement. A regional average, a national average, and a receipt from one fuel stop are different inputs. Save the displayed week and value used for each calculation; a later visit to the EIA page may show a newer week.
Choose the baseline from the fuel assumption in the base rate, then agree on the MPG used to translate a per-gallon change into a per-mile change. Neither figure comes automatically from EIA. If you need to understand the underlying operating expense, use the trucking cost-per-mile calculator separately. A fuel adjustment covers the change above the agreed baseline under this formula, not the entire fuel bill.
The rate terms should also say which miles count. One agreement may use loaded miles from a named routing method; another may include an empty repositioning leg. Record the method and mileage, especially if the planned route changes. Agree on the reference week before tender so a newly published price cannot silently change the calculation for an existing load.
Work a load through the formula
This example uses invented terms and prices. It is not an EIA quote or a recommended rate. Suppose the agreement has a $4.20 per gallon baseline, a $4.92 benchmark, 6 MPG, and 525 eligible loaded miles. It sets negative adjustments to zero and rounds only the trip total to cents.
- Price difference: $4.92 − $4.20 = $0.72 per gallon.
- Per-mile adjustment: $0.72 ÷ 6 MPG = $0.12 per mile.
- Trip surcharge: $0.12 × 525 eligible miles = $63.00.
A load record for this example would name the benchmark as “EIA U.S. on-highway diesel, week of [YYYY-MM-DD],” then replace the placeholder and illustrative $4.92 with the actual published week and value agreed for the load. It would also retain the $4.20 baseline, 6 MPG, 525 eligible miles and mileage method, zero floor, rounding rule, and $63.00 result. The carrier packet checklist shows where to keep the agreement and related documents together.
If the benchmark were below the baseline, this example’s zero floor would produce no surcharge. An agreement that allows a negative adjustment would instead produce a credit. The calculator can show either result, but its default is the zero floor. It multiplies the full per-mile result before rounding the displayed trip total. Follow the contract if it requires rounding each rate first, a price bracket, a percentage of linehaul, a cap, or another method.
Check the rate and keep the evidence
Before the rate confirmation is accepted, check whether fuel is a separate line item or already included in the quoted total. Adding a surcharge to an all-in rate without agreeing to that treatment can count the same fuel adjustment twice. State the calculation method, source week, and effective rule in the confirmation, then make the invoice match those terms.
Keep enough detail to repeat the calculation later:
- The agreed base rate, baseline, MPG, eligible-mile rule, credit rule, and rounding method.
- The benchmark series link, region, published week and value, plus the date you captured it.
- The mileage source, load miles, arithmetic, and trip adjustment.
- The rate confirmation, invoice, and any later agreed change.
The document carrier review explains how to make a dated decision record. If the named carrier or dispatcher changes before movement, use HaulFacts lookup to reconcile the entity and follow the pre-pickup checklist for the shipment handoff.
An EIA average measures a published market price rather than the carrier’s receipts. The agreed fuel terms determine the invoice amount. Other agreements use different surcharge methods.