Free tools · Fuel surcharge · How it works

How a fuel surcharge is calculated

A per-mile fuel surcharge is the diesel price above the contract's base price, divided by the truck's MPG: (current diesel − base) ÷ MPG.

The three numbers

Base fuel price — the diesel price written into the contract as the starting point. Fuel up to this price is treated as already covered by the linehaul rate.
Current diesel price — the price for the week, usually a published weekly average (national or regional, whichever the contract names).
MPG — miles per gallon. Some contracts set a fixed MPG; others use the truck's.

The math, step by step

Subtract the base price from the current diesel price. That's the extra cost per gallon.
Divide by MPG. Each mile burns 1 ÷ MPG gallons, so this gives the extra cost per mile.
If the result is below zero (diesel under the base), the surcharge is zero.
Multiply the per-mile figure by the miles the surcharge is paid on for a trip total.

Worked example

Example numbers only — not this week's diesel price.

Example diesel: $3.80/gal
Example base: $1.20/gal
Example MPG: 6.5
Example miles: 800

$3.80 − $1.20 = $2.60 per gallon above base
$2.60 ÷ 6.5 MPG = $0.400 per mile
$0.400 × 800 miles = $320.00 fuel surcharge for the trip

Other ways contracts figure it

The per-mile formula above is a common way to figure it. Some contracts use a step table instead — the surcharge moves a fixed amount per mile for each set jump in diesel — and some pay a percentage of the linehaul. Those follow the schedule in the contract, so their figures can differ from the formula.

To run the formula at this week's diesel price, use the fuel surcharge calculator. To see it across a range of prices at once, see the fuel surcharge table.

Fuel surcharge questions

How do you figure a fuel surcharge per mile?

Subtract the contract's base fuel price from the current diesel price, then divide by MPG. With example numbers — $3.80 diesel, a $1.20 base, 6.5 MPG — that's ($3.80 − $1.20) ÷ 6.5 = $0.400 per mile.

What is the base fuel price in a fuel surcharge?

It's the diesel price written into the contract as the starting point. Fuel cost up to the base is treated as part of the linehaul rate; the surcharge covers the price above it. $1.20 per gallon is a common base, and some contracts use $1.25 or $1.50.

What happens to the fuel surcharge when diesel is below the base price?

Under the per-mile formula it's zero — the result can't go negative. At $1.10 diesel against a $1.20 base, the surcharge is $0.000 per mile.

How do you get the fuel surcharge for a whole trip?

Multiply the per-mile surcharge by the miles the contract pays it on. With the example above, $0.400 per mile over 800 miles is $320.00.

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