What is a fuel surcharge?

A fuel surcharge (FSC) is an extra charge carriers add to the base freight rate to recover volatile diesel costs. It is usually published as a percentage tied to a national average diesel price index, updated weekly or monthly.

How is the percentage surcharge calculated?

Multiply the base line-haul rate by the published FSC percentage. A 1200 base rate with a 28.5 percent surcharge adds 342, for a total of 1542. Most LTL carriers post a current FSC percent that you apply this way.

How does the diesel peg table work?

Carriers set a peg price below which no surcharge applies. For every fixed increment the average diesel price rises above the peg, a set number of percentage points is added. For example, every 6 cents above 1.25 might add 0.5 percent.

Where do I find the diesel price index?

In the US, carriers reference the EIA national average on-highway diesel price, published every Monday. Many FSC schedules lag a week, so use the index date your carrier's tariff specifies when verifying an invoice.

Why verify the surcharge myself?

Fuel surcharges are a common source of overbilling because the percentage moves weekly and is applied to a base that varies by lane. Recomputing it from the published index lets you catch errors and budget accurately.

What is the Freight Fuel Surcharge Calculator?

Apply a published fuel surcharge index percentage to a base freight rate, or build the surcharge from a diesel peg and step table. Freight brokers and shippers use this to verify carrier invoices and budget fuel costs. Runs in your browser. It runs free in your browser on Gera Tools, with nothing uploaded.

Freight Fuel Surcharge Calculator

Name: Freight Fuel Surcharge Calculator
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

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Fuel surcharges move every week and ride on top of every freight invoice, which makes them an easy place for billing errors to hide. This calculator works both ways: apply a published surcharge percentage to a base rate, or build the percentage up from a diesel peg and step schedule.

How it works

Method 1 — Percentage FSC. The most common approach: the carrier publishes a single FSC percentage (updated weekly) and you multiply it against the base line-haul rate:

surcharge = base rate × (FSC% / 100)
total     = base rate + surcharge

Method 2 — Diesel peg table. Some tariffs define the surcharge by how far the current diesel price sits above a peg price, in fixed increment steps:

over      = max(0, dieselPrice − pegPrice)
steps     = floor(over / increment)
FSC%      = steps × stepPercent
surcharge = lineHaul × (FSC% / 100)

If you provide trip miles and vehicle fuel economy instead of a line-haul dollar amount, the tool estimates the actual extra fuel spend above the peg across the whole trip.

Worked examples

Example 1 — Simple percentage method. Base rate: $1,200. Published FSC: 28.5%. Surcharge = $1,200 × 0.285 = $342. Total invoice = $1,542.

Example 2 — Peg table method. Peg price: $1.25/gallon. Current EIA diesel: $4.10/gallon. Increment: 6 cents. Step percent: 0.5%. Over peg: $4.10 − $1.25 = $2.85. Steps: floor($2.85 / $0.06) = 47. FSC% = 47 × 0.5% = 23.5%. Applied to a $1,000 line-haul: surcharge = $235, total = $1,235.

When and why to use this tool

Invoice verification. Fuel surcharges are one of the most common sources of freight overbilling. Carriers sometimes apply last week’s FSC percentage to this week’s invoice, or use a higher bracket than the index supports. Running the calculation yourself takes 30 seconds and catches errors before they become a habit.

Budget forecasting. When quoting a lane several weeks in advance, model a range of diesel prices through the peg table to see how the FSC changes under optimistic, base, and pessimistic fuel scenarios.

LTL vs truckload comparison. LTL carriers often publish a different FSC schedule than TL carriers, making a direct cost comparison tricky. Normalise both to the same diesel price using this tool before comparing total lane costs.

Important caveats

The EIA national average on-highway diesel price (published each Monday) is the most common index US carriers use, but not universal — some carriers reference the regional average, which can differ by $0.10–$0.20/gallon.
Verify the lag built into your carrier’s tariff: most schedules reference the price from the prior Monday or even two Mondays back. Applying the wrong week’s price is the most common error in manual verification.
FSC applies to the line-haul rate, not to accessorial charges (fuel, lift-gate, residential delivery), though some carriers structure it differently. Check your tariff’s definition of the FSC base.