A fuel surcharge is a variable fee added to a base freight rate to account for changes in diesel fuel prices. It is recalculated weekly or monthly depending on the carrier.
For most truckload shipments, fuel surcharges add 20 to 40 percent to the base rate. On a slow freight market with low base rates, the fuel surcharge can exceed the line-haul charge. Understanding how it works helps shippers forecast freight spend and avoid invoice surprises.
How Fuel Surcharges Are Calculated
The most common method uses the weekly US diesel retail price published every Monday by the US Energy Information Administration (EIA). Carriers maintain an index table that maps diesel price ranges to surcharge percentages. When diesel is at $3.50 per gallon, the surcharge might be 18 percent. When it hits $5.00, the surcharge might be 30 percent.
The surcharge is applied as a percentage of the base rate (line-haul), not the total invoice. So if a load costs $2,000 base and the fuel surcharge is 25 percent, the fuel surcharge is $500 — bringing the total to $2,500 before accessorials.
Why Fuel Surcharges Exist
Carriers cannot absorb diesel price swings in their base rates without either losing money or overcharging when prices fall. The fuel surcharge mechanism separates the fixed cost of operating a truck from the variable cost of fuel, allowing base rates to stay stable while fuel cost recovery adjusts automatically.
LTL vs FTL Fuel Surcharges
FTL fuel surcharges are applied as a percentage of the base rate and are specific to each carrier contract. Spot market FTL rates often include fuel in the quoted all-in rate, which makes comparison easier but obscures changes over time.
LTL fuel surcharges are published in carrier tariffs and apply to every LTL shipment based on the current week's diesel price. LTL surcharges tend to be higher because LTL operations involve more stops, more idle time, and lower fuel efficiency per freight unit than FTL.
Fuel Surcharges in Reefer Freight
Refrigerated freight carries an additional component in its fuel surcharge: the diesel burned by the refrigeration unit itself. Reefer trucks run the refrigeration engine continuously during transit. This adds fuel cost that is recovered either through a separate reefer charge or embedded in a higher overall surcharge rate.
How to Forecast Fuel Surcharge Impact
Review the carrier's fuel surcharge index before committing to a rate. Ask what the surcharge is at the current diesel price and what it would be if diesel rises by $0.50 and $1.00. Model the impact on your freight budget across both scenarios. Most freight budgets that "break" in a fuel spike did not model surcharge sensitivity at all.
Frequently Asked Questions
Is the fuel surcharge negotiable?
The surcharge rate applied to the base rate can be negotiated in carrier contracts. Some shippers negotiate a surcharge cap — a maximum percentage regardless of how high diesel climbs. This transfers some risk to the carrier and requires volume commitment in exchange.
Do brokers add fuel surcharges on top of carrier fuel surcharges?
No. The fuel surcharge is included in the rate the broker passes to the shipper. A transparent broker will explain how the surcharge is calculated on any load you book with them.
Where can I check the current diesel price?
The EIA publishes the US weekly diesel retail average every Monday at eia.gov. This is the standard reference used by most carriers.
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