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Fuel Surcharge Calculator

Enter the current diesel price, your contract's base (peg) price, and your truck's real MPG to get your fuel surcharge per mile — and the total on any load. Pre-filled with the current EIA national diesel average so you can see today's number instantly.

FSC per mile
FSC on this load
Gallons (this load)
Enter the numbers to see your surcharge.

FSC per mile = (current price − peg) ÷ MPG, floored at $0. Current price is pre-filled with the EIA national diesel average ($5.967/gal, week of Sep. 7, 2026; published Sep. 9) — replace it with today's number or your region's price. Use diesel by state for regional prices.

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How a trucking fuel surcharge works

A fuel surcharge (FSC) is the adjustable add-on that protects you when diesel rises. It's tied to a base (peg) price in your contract: below the peg there's no surcharge; above it, the surcharge grows as diesel climbs. The standard method is per mile: take the current diesel price minus the peg, divide by an assumed MPG, and you get the surcharge per paid mile. Most carriers reset it weekly using the U.S. Energy Information Administration (EIA) national average.

The formula

  1. Surcharge per mile = (current diesel price − base/peg price) ÷ MPG.
  2. Surcharge per load = surcharge per mile × load miles.
  3. If current price is below the peg, the surcharge is $0.

Example: at $5.967/gal current, a $1.25 peg, and 6 MPG → ($5.967 − $1.25) ÷ 6 = $0.79 per mile. The lower your real MPG, the higher your surcharge — because you burn more gallons per mile.

Diesel in 2026 — why this matters now

The U.S. on-highway diesel average was $5.967/gallon for the week of September 7, 2026, up 36.8¢ from the prior week (EIA). At that price, fuel surcharge is a large slice of a load's revenue — and a real MPG that's even half a mile per gallon better, or a fuel-card discount, drops straight to your bottom line. Chasing a bigger surcharge matters less than burning fewer gallons.

Frequently asked questions

How is a fuel surcharge calculated?

(Current diesel − base peg) ÷ MPG = surcharge per mile, updated weekly off the EIA national diesel average.

What is the base/peg price?

The diesel price above which the surcharge starts, set in the contract — classically ~$1.25/gal, though many schedules use a higher base.

What's the fuel surcharge per mile right now?

About $0.79/mile at the $5.967 EIA diesel average, a $1.25 peg, and 6 MPG (week of September 7, 2026). Yours depends on your peg and real MPG.

Methodology & sources

Standard per-mile peg method; current diesel default is the EIA national on-highway average ($5.967/gal, week of Sep. 7, 2026; published Sep. 9). Sources: U.S. EIA Gasoline and Diesel Fuel Update. Last updated September 2026. Estimates for planning only. Built by TruckMargin.