Skip to main content
Complete Guide

Fuel Surcharge Formula: How to Calculate FSC

The definitive guide to calculating fuel surcharges in trucking. Learn the industry-standard formula, understand each variable, and calculate accurate per-mile surcharges.

The Standard Fuel Surcharge Formula

Industry-Standard Formula
FSC per Mile = (Current Price - Baseline) ÷ MPG

This formula is used by the majority of trucking companies, freight brokers, and owner-operators in the United States. It calculates a per-mile surcharge that adjusts with fluctuating diesel prices, providing fair compensation for fuel costs.

Why This Formula Works

This formula directly ties the surcharge to actual fuel cost increases. When diesel prices rise above the baseline, the surcharge compensates for the additional fuel expense per mile traveled.

Understanding Each Variable

Current Diesel Price

The current national or regional retail price of on-highway diesel fuel. Most contracts reference the DOE/EIA Weekly Retail On-Highway Diesel Price, published every Tuesday by the U.S. Energy Information Administration.

Current National Average
~$3.60/gallon

Baseline Price

The reference diesel price set in your carrier contract. This is the price at whichno surcharge applies. Common baselines range from $1.10 to $1.50 per gallon.

Typical Range
$1.10 - $1.50
Industry Standard
$1.20

Miles Per Gallon (MPG)

The average fuel efficiency of the truck. Most contracts use 6 MPG as the standard for loaded tractor-trailers. This accounts for varying terrain, weather, and load weights.

Empty
7-8 mpg
Standard
6 mpg
Heavy Load
5-5.5 mpg

Step-by-Step Calculation

1

Get the Current Diesel Price

Check the DOE/EIA weekly diesel price. Most carriers update their surcharges on Tuesday or Wednesday after the new price is published.

Example: Current price = $3.60/gallon
2

Identify Your Baseline Price

Find the baseline in your carrier contract or rate agreement. If not specified, use the industry standard of $1.20.

Example: Baseline = $1.20/gallon
3

Calculate Price Above Baseline

Subtract the baseline from the current price. This is the excess fuel cost.

$3.60 - $1.20 = $2.40 above baseline
4

Divide by MPG

Divide the excess by fuel efficiency to get the per-mile surcharge.

$2.40 ÷ 6 mpg = $0.40 per mile
5

Multiply by Trip Miles

Multiply the per-mile surcharge by total trip distance.

$0.40 × 500 miles = $200.00 total FSC

Real-World Examples

Example 1: Standard Contract

Given:
  • Current Diesel: $3.85/gal
  • Baseline: $1.20/gal
  • MPG: 6
  • Trip Distance: 750 miles
Calculation:
($3.85 - $1.20) ÷ 6 = $0.4417/mi
$0.4417 × 750 = $331.25

Example 2: Owner-Operator with Lower Baseline

Given:
  • Current Diesel: $3.60/gal
  • Baseline: $1.10/gal
  • MPG: 5.5 (heavy haul)
  • Trip Distance: 1,200 miles
Calculation:
($3.60 - $1.10) ÷ 5.5 = $0.4545/mi
$0.4545 × 1,200 = $545.45

Formula Variations by Carrier

While the per-mile formula is most common, some carriers use alternative methods:

CarrierBaselineMPGNotes
Swift Transportation$1.256.5Higher efficiency assumed
J.B. Hunt$1.206.0Industry standard
Schneider National$1.156.0Lower baseline
Werner Enterprises$1.226.0Slightly higher baseline
Always Check Your Contract

Carrier formulas can vary by contract, lane, and customer. Always verify the specific terms in your rate agreement.

Common Mistakes to Avoid

Using pump prices instead of DOE prices

FSC calculations should use the official EIA/DOE weekly average, not local pump prices.

Forgetting to update weekly

DOE prices change every Tuesday. Using outdated prices costs you money.

Applying surcharge when diesel is below baseline

If current price is below baseline, the surcharge is $0—not negative.

Using the percentage formula for per-mile calculations

Some contracts use percentage-based FSC. Don't mix up the formulas.

Calculate Your Fuel Surcharge Now

Use our free calculator with live DOE diesel prices and carrier presets.

Open Calculator