What Is a Fuel Surcharge and How Is It Calculated?

If you've ever looked at a freight invoice and wondered why the rate you were quoted isn't what you paid — fuel surcharges are usually the reason. Here's exactly how they work.

What Is a Fuel Surcharge?

A fuel surcharge (FSC) is a variable fee added to base freight rates to cover the cost of diesel fuel. Because diesel prices change weekly, carriers and brokers add a surcharge that adjusts with the market rather than baking an uncertain fuel cost into the base rate.

Fuel typically represents 25–35% of a carrier's total operating cost. When diesel spikes, carriers pass that cost to shippers through the FSC.

How Is It Calculated?

Most carriers and brokers use the Department of Energy (DOE) weekly retail diesel price as the benchmark. The surcharge is then applied as a percentage of the linehaul rate or as a cents-per-mile figure.

Example: If diesel is $3.80/gallon and the carrier's FSC table says that triggers a 28% surcharge, a $2,000 linehaul rate becomes $2,560 all-in.

The DOE publishes updated diesel prices every Monday at eia.gov. Most carriers update their FSC tables weekly based on this number.

FSC vs All-In Rates

Some brokers (including IZY Logistics) quote all-in rates — the fuel surcharge is already included in the number you see. Others quote a base rate and add FSC separately on the invoice. Always ask which method your broker uses before approving a quote.

All-in pricing is cleaner and eliminates surprises on the invoice. If a broker is quoting you a base rate, ask: "What is the FSC and what is it based on?"

How to Minimize Fuel Surcharge Impact

• Book when diesel is low — FSC is lowest in winter when demand drops. If you can move non-urgent freight in January vs June, you'll pay less.
• Use contract rates — Contract pricing often includes a fixed FSC cap. Spot rates fluctuate with the market.
• Consolidate shipments — Moving one FTL instead of two LTL loads reduces total FSC exposure.
• Ask for all-in pricing — Eliminates invoice surprises and makes budgeting easier.

Fuel Surcharge Levels in 2026

Diesel climbed sharply through 2026: the DOE weekly national average set a new record of $6.53 a gallon on September 21, 2026, above the 2022 peak, so fuel surcharges are well above normal levels. Always ask how your FSC is calculated.