Calculate the per-mile surcharge that covers fuel above your baseline price.
A surcharge stops a fuel spike from eating a rate you agreed months ago. The maths is simply the gap between today's diesel and the base price built into your linehaul, divided by your MPG — use a published index like the DOE weekly average so the number survives an audit. The input nobody checks is the base price, and it decides whether the whole thing works: if your linehaul was priced when diesel sat at $3.00 but your surcharge still bases at $1.25, you are billing a surcharge on $1.75 a gallon your linehaul already covered. Review the base every renegotiation, not just the table.
The things carriers ask most about this calculation.
Subtract your base fuel price from the current price, then divide by your truck's MPG. That gives the extra cost per mile, which you bill on top of linehaul. At $5.45 diesel, a $1.25 base and 6.5 MPG, the surcharge is about 65 cents per mile.
Whatever price is already built into your linehaul rate. The most-cited industry baseline is $1.25 to $1.50, though contracts repriced after 2022 often reset it as high as $2.50 to $3.50. If your base is unrealistically low, your surcharge does the work your linehaul should be doing.
Most surcharge schedules key off the DOE weekly national average, published every Monday. Using a national index rather than what you paid at a particular pump keeps the calculation auditable for both sides.
Usually not. Most schedules pay surcharge on loaded miles only, which is another reason to price deadhead into your linehaul rather than expecting fuel recovery to cover it.

