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Trucking tools / 03

Fuel surcharge
calculator.

Turn a change in diesel price into a per-mile adjustment and trip total. Use the baseline, fuel economy, and mileage agreed in your contract.

Set your assumptions

USD · US gallons · miles

The starting numbers are an example, not a live diesel price or a recommended contract.

Fuel price already covered by your base rate.
Use your contract's index, region, and reference week. Find EIA diesel prices.
Enter MPG greater than zero, using your agreement or planning assumption.
Include empty miles only if your agreement covers them.
This note appears on your printout. Your entries stay in this page and clear when you reload.
Your calculation

Fuel adjustment

$0.2500per mile

25.00 cents per mile

Trip surcharge$125.00for 500 eligible miles
Price difference
$1.500/gal
Below-baseline rule
Stop at $0

The trip total uses the unrounded rate. Your agreement may specify a different rounding rule, price bracket, or percentage formula.

The calculation

How the surcharge is calculated

(diesel price − baseline) ÷ MPG
= adjustment per mile

Multiply the per-mile adjustment by eligible miles for the trip total. When credits are off, a negative price difference becomes zero.

A worked example

At $4.00 per gallon, a $2.50 baseline leaves a $1.50 difference. Divide by 6 MPG to get $0.25 per mile. For 500 eligible miles, the surcharge is $125.00.

This adjustment covers the increase above the baseline. It does not represent the trip's whole fuel bill. Use the cost-per-mile calculator to account for fuel alongside your other operating expenses.

Before you use it on a rate confirmation

Which diesel price should I enter?

Use the index and reference date stated in your agreement. If it calls for EIA's national average, a regional price or a receipt from one fuel stop is a different input. EIA publishes weekly diesel benchmarks; this calculator does not fetch them automatically. Record the reference week in the optional note so you can check the calculation later.

Is this the surcharge my customer owes?

Your agreement determines that. EIA explains that companies negotiate fuel surcharges privately. This tool uses a per-mile price-difference formula. It does not apply percentage-of-linehaul schedules, bracket tables, minimums, caps, or separate reefer fuel charges.

Can I add it to an all-in rate?

Check what that rate includes before adding another charge. If fuel is already included, adding this amount would count it twice. Confirm the fuel terms with the counterparty and keep them with the rate confirmation. Our carrier packet checklist explains which documents to keep together.

How should I round it?

This calculator displays four decimal places for dollars per mile and two for the trip total. It multiplies the full rate before rounding the displayed total. If your contract rounds the per-mile rate first or uses price bands, calculate the invoice under those terms.

Formula reference: OOIDA's fuel surcharge calculation. Benchmark and contract context: U.S. Energy Information Administration. Sources checked September 11, 2026.