How to use this calculator
- Enter diesel prices. Set the current diesel price and the base price where the contract surcharge starts.
- Set MPG assumptions. Use the contract MPG basis for surcharge math and actual route MPG for recovery math.
- Enter route miles. Add billable miles, deadhead or unpaid miles and the number of similar loads in the period.
- Apply floor or cap. Leave the minimum at zero and cap high unless your agreement uses a floor or maximum per-mile surcharge.
- Read the recovery margin. Compare total fuel surcharge with the incremental fuel cost across all operating miles.
How it works
This trucking fuel surcharge calculator uses a common per-mile surcharge structure, but keeps the contract-specific values visible. The diesel price spread is:
spread = max(current_price - base_price, 0)
The formula surcharge divides that spread by the contract MPG basis. Any minimum floor or maximum cap you enter is then applied:
FSC_per_mile = clamp(spread / MPG_s, min_FSC, max_FSC)
Total fuel surcharge is applied to billable miles only:
total_FSC = FSC_per_mile x billable_miles x loads
Recovery margin compares that surcharge with the incremental fuel cost on all operating miles, including deadhead or unpaid miles:
recovery_margin = total_FSC - ((operating_miles / MPG_a) x spread)
Worked example
Verified against the live calculator
A lane has a $4.25/gal current diesel price and a
$1.25/gal base price, so the spread is $3.00/gal.
With a 6.0 mpg surcharge basis, the formula surcharge is
$0.50/mi. On 500 billable miles, one load
earns a $250 fuel surcharge. If actual route MPG is
6.5 and the truck also runs 50 deadhead miles,
the diesel-price increase is about $253.85, leaving a
small negative recovery margin.
Frequently asked questions
How do you calculate a trucking fuel surcharge?
A common per-mile method is max(current diesel price minus base diesel price, 0) divided by the contract MPG basis. This calculator then applies any floor or cap you enter and multiplies by billable miles.
Why does actual MPG differ from surcharge MPG?
The surcharge MPG is the contract divisor. Actual MPG is the fuel economy you expect on the lane, and it is used here only to compare surcharge recovery against the real fuel-cost increase.
Does this use the DOE diesel price?
No. Enter the current diesel index, pump-card price or contract price your agreement uses. The calculator does not fetch live diesel data or choose a state, region or publication date.
Does deadhead receive fuel surcharge?
Not in this screen. Deadhead or unpaid miles are included in fuel-cost recovery math but the surcharge is applied only to billable miles.
Method & assumptions
- Formula-only trucking fuel surcharge screen from values you enter.
- No live DOE/EIA diesel index, carrier tariff, shipper contract, regional diesel table, accessorial schedule or tax rule is embedded.
- Per-mile surcharge is applied only to billable miles. Deadhead and unpaid miles affect recovery margin but do not earn surcharge in this screen.
- Actual billing may use weekly tables, rounding bands, regional indexes, caps, floors, discounts, detention, reefer fuel, tolls, IFTA, accessorials or contract exceptions.
- Use fleet fuel cost, freight density and truckload capacity tools for adjacent route and freight planning.