Shipping economics

Fuel Surcharge Calculator

Carriers index fuel surcharges to the DOE weekly diesel price. Your contract specifies a benchmark price and a cents-per-mile or percentage schedule — this computes the surcharge either way.

Direct answer

What does this tool do?

Fuel Surcharge Calculator computes the result directly in your browser — Carriers index fuel surcharges to the DOE weekly diesel price. Your contract specifies a benchmark price and a cents-per-mile or percentage schedule — this computes the surcharge either way. Nothing you enter is uploaded or stored.

Reviewed by BoringToolsKit · September 1, 2026 · Example rates, editable — not carrier quotes.

Quick answer

How the estimate works

Percentage method: surcharge = base freight × surcharge %. Cents-per-mile method (truckload): surcharge = (current DOE price − benchmark) ÷ benchmark MPG × miles. Both are modeled.

Calculator

Fuel surcharge

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Rate tables below are editable example defaults for modeling, not carrier quotes. Actual prices vary by negotiated rates, surcharges, and season. Confirm final cost with the carrier before shipping.

Methodology

Formula and assumptions

Percentage method: base × surcharge %. Cents-per-mile: (current DOE $/gal − benchmark) ÷ truck MPG = $/mile, × miles. The DOE diesel index publishes weekly (Monday, effective the following week). Contracts define the benchmark price and schedule — read yours.

Quick answers

Fuel Surcharge Calculator questions

How is a fuel surcharge calculated?

Two ways: a percentage of the base freight, or cents-per-mile from the DOE diesel index spread over truck MPG. Truckload uses CPM; LTL and parcel mostly use percentages.

Where does the DOE diesel price come from?

The US Energy Information Administration publishes the weekly retail diesel price every Monday. Contracts peg the surcharge schedule to it, often with a lag week.

Why did my fuel surcharge go up when diesel fell?

Contracts often use a lagged index, floor prices, or quarterly averages. Check which benchmark week your carrier's schedule references.

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Worked example: a 850-mile truckload shipment

Say your contract sets a benchmark of $1.20/gal, the DOE diesel index prints $3.90/gal this week, and your truck averages 6.0 MPG. The spread is $3.90 minus $1.20 = $2.70/gal. Divided by 6.0 MPG, that is $0.45 per mile. On an 850-mile lane, the surcharge is 0.45 x 850 = $382.50, or about $0.45 for every mile the truck turns.

Now a percentage lane: base freight of $2,400 at a 22% surcharge adds 2,400 x 0.22 = $528. If the same load ran under the CPM contract above, total fuel would be $382.50, so the two methods can differ by $145.50 on identical freight. That gap is why shippers compare contract types, not just headline rates, before booking a lane.

Check the arithmetic either way: divide the surcharge by miles ($382.50 / 850) and you get back $0.45, confirming the per-mile rate was applied correctly.

Where estimates diverge from the invoice

The biggest surprise source is the lag week. A contract referencing the index from two weeks ago means the $3.90 print on Monday may not hit your invoice until the week after next; during a price swing of $0.15/gal per week, that lag alone shifts a 2,000-mile shipment by 0.15 / 6.0 x 2,000 = $50.

Floor prices and brackets also break the formula. Many schedules step in $0.04/gal increments, so a DOE move from $3.88 to $3.91 still lands in the same bracket and changes nothing, while a crossing from $3.91 to $3.93 jumps a whole step. A minimum fuel surcharge (commonly 20-25% or a fixed floor near $1.25/gal benchmark) keeps the charge positive even when diesel is cheap.

Finally, surcharge usually applies only to linehaul, not to accessorials. A $285 liftgate fee or $95 detention charge typically goes unsurcharged, while residential delivery fees sometimes are. On a $1,100 LTL invoice with 24% surcharge, fuel adds $264 to linehaul, so an extra 6% tacked onto accessorial fees would move the total by roughly $22 to $23. Ask which charges the percentage applies to before reconciling.