How the peg method works
Fuel surcharge programs exist to pass diesel price volatility from carrier to shipper without renegotiating the base linehaul rate every time fuel moves. A peg price (also called a base or trigger price) is fixed into the contract — it's the diesel price the linehaul rate already assumes is "baked in." Every dollar diesel trades above that peg gets converted to a per-mile add-on using the truck's fuel economy.
FSC / mile = max( 0 , (current diesel $/gal − peg $/gal) / truck MPG )
Total FSC = FSC / mile × loaded miles
- Why divide by MPG: a truck averaging 6 MPG burns one gallon every 6 miles, so each extra dollar-per-gallon above peg costs the carrier $1 ÷ 6 = $0.1667 per mile in added fuel spend. Better MPG (say 7.5) lowers that per-mile add-on; worse MPG raises it.
- Why it floors at zero: if diesel drops below the peg, the surcharge doesn't go negative and start subtracting from the linehaul rate — it simply doesn't apply. The base rate already reflects the peg price as the "included" fuel cost.
- Peg prices vary by contract. $1.25/gal is a commonly used legacy peg in trucking contracts (it dates back to when $1.25 diesel was closer to "normal"), but many current contracts use a higher peg (e.g. $2.50–$3.50) to reflect today's price environment, or update the FSC weekly against the EIA average with no peg at all — always use the peg written into your specific rate confirmation or contract.
- Update cadence: most FSC schedules reset weekly, tied to the EIA's national average diesel price — a Monday price the EIA publishes Tuesday morning (~10:00 a.m. ET; the Wednesday after a Monday holiday) — and apply to the following week's loads.
Source: EIA Weekly Retail Gasoline and Diesel Prices (U.S. No. 2 Diesel, all types), U.S. Energy Information Administration — the industry-standard diesel benchmark most FSC schedules reference.
eia.gov/petroleum/gasdiesel. This tool does not auto-fetch the live price: EIA's public API (api.eia.gov) requires a free registered API key per user, which cannot be safely embedded in a static public page — enter the current published price manually.
How this tool works
Fuel Surcharge (FSC) Calculator runs entirely in your browser. Inputs are evaluated with rules and constants taken from Trucking Diesel Surcharge Tool (Freight & logistics). Nothing is uploaded to a server for the calculation itself.
- Enter the values that match your load, vehicle, or scenario.
- Results update live — treat them as a cited reference, not legal or professional advice.
- Open the primary source linked at the top of this page before you rely on a number for compliance.
Use Copy link to share this page (including query parameters when the tool supports them) or Print for a dock/packet copy.
FAQ
Where does diesel come from?
Use the DOE/EIA diesel benchmark your contract cites, or your own base+trigger schedule. This tool computes the surcharge math — it does not scrape live prices unless labeled.
Can I cite this in a claim or customer email?
You can share the link and the underlying public source. Do not present the tool as legal, medical, or insurance advice.
Can I cite this in a claim or customer email?
You can share the link and the underlying public source. Do not present the tool as legal, medical, or insurance advice.