Fuel Surcharge Explained: How It's Calculated

Diesel is one of your biggest costs, and it moves every week. The fuel surcharge is how the freight market passes some of that cost to the shipper, so carriers aren't stuck absorbing every price spike.

But on spot freight it's often rolled into one number, and the way it's quoted can make two similar loads look very different. Here's how it works and how to read it.

What a fuel surcharge is

A fuel surcharge (FSC) is pay on top of the linehaul that rises and falls with diesel prices. In contract freight, the shipper and carrier or broker agree on a fuel schedule, and the surcharge is recalculated as prices change. In spot freight, many brokers quote one all-in rate, with fuel built in, while others list linehaul and fuel separately on the rate confirmation.

Either way, the idea is the same: the linehaul pays for the truck, the driver and the margin, and the fuel surcharge covers fuel above a baseline price.

How it's calculated

Most fuel surcharge schedules are built on the U.S. Energy Information Administration's weekly on-highway diesel price, published every Monday as a national average and by region. A common formula is:

• Current diesel price: the EIA weekly average the schedule uses, national or regional.
• Base price: the diesel price already covered by the linehaul. Below it, no surcharge is paid. Shippers set their own base.
• Miles per gallon: an assumed fuel economy, often around 6 mpg. A lower mpg in the formula pays a higher surcharge.

Some schedules use a lookup table instead, with a set surcharge for each price band, but the logic is the same.

A worked example

Say a shipper's schedule uses a base price of $1.25 a gallon and 6 mpg, and this week's diesel average is $6.25.

Example numbers only. Every schedule sets its own base price, mpg and update timing.

If diesel rises to $6.85 the next week, the surcharge becomes about $0.93 a mile, or $840 on the same load, while the linehaul stays the same.

When diesel falls, and regional prices

Fuel surcharge works in both directions. When diesel drops, the surcharge drops with it, and on all-in spot rates brokers often lower their offers quickly. Keep an eye on the weekly price trend so you know whether a lower offer reflects cheaper fuel or just a weaker market.

Prices also vary by region. The EIA publishes averages for the East Coast, Midwest, Gulf Coast, Rocky Mountain and West Coast regions, and California is usually the most expensive.

A schedule based on the national average can underpay you on West Coast runs and overpay slightly in the Gulf. If you run one region most of the time, compare your real fuel cost to the index your loads use.

Fuel surcharge on spot loads

On the spot market, how much of a load's pay is "fuel" is often a matter of how the broker presents it. A broker may quote $3,000 all-in, or $2,250 linehaul plus $750 fuel. The money is the same, but the split matters for three reasons:

1. Comparing loads. You need to compare all-in to all-in, or linehaul to linehaul.
2. Fees. Some dispatchers and factors charge on the whole amount, others on linehaul only.
3. Rising diesel. On a spot load the rate is locked when you book. If diesel jumps before you fuel up, you absorb it, so price loads with current fuel in mind.

Ask the broker how the rate breaks down, and make sure the rate confirmation shows it. Here's what every line on a rate con means.

Comparing all-in and linehaul rates

Market reports usually show both. In DAT's data for the week of October 10 to 16, 2026, the national dry van spot average was $3.09 a mile all-in and $2.26 linehaul, so fuel made up about 83 cents of every mile. Our monthly rate report shows both numbers for van, reefer and flatbed.

When you check a rate against your own operating cost per mile, compare all-in to all-in: your cost per mile already includes fuel. When you're checking how much the linehaul itself pays for your truck and time, strip out the fuel.

How dispatch fees treat fuel surcharge

Dispatchers charge their percentage on different amounts. Some charge on linehaul only. Others, including us, charge on the full amount the broker pays, fuel surcharge included. Either can be fair if it's in writing, but the basis changes what you pay, especially when diesel moves:

Over a year, that difference adds up to thousands of dollars. Ask any dispatcher what their fee is charged on before you sign. Our guide to dispatcher fees covers the rest.

Making the most of it

• Know your real fuel cost per mile, from your own mpg and fuel receipts, not the schedule's assumption.
• Watch the EIA weekly price when you book. A rate that worked last month may not this week.
• Ask for the split on every rate con, so you can compare loads and fees fairly.
• Improve your mpg. When the surcharge assumes 6 mpg and you get 7, the difference stays in your pocket.
• Use fuel discount programs where they make sense. They lower your cost without changing what the broker pays.

Our own fee is a flat 6% or 8% of your weekly gross, which includes fuel surcharge. We put that in writing before you sign, so you can run the numbers yourself.