Fuel Surcharge Calculator
A fuel surcharge two ways: per mile or km from the fuel-price difference and fuel economy, or a stepped percentage of the linehaul from your carrier’s rule.
Surcharge per mile/km and for a trip (price difference × fuel per distance), or the stepped percentage with a cap and the amount on the linehaul — base price, step and rate all yours.
Example: Diesel at $4.10 against a $3.50 base in a 6.5 mpg truck adds $0.092 per mile, $46 on 500 miles; as a table, 0.60 over base in $0.10 steps at 0.5 % each is 3 %, capped at your 2.5 %.
Two ways carriers
write the same idea.
The per-distance rule, the stepped percentage table, and why every parameter is a field.
Per distance
A base rate already includes fuel at some base price. When fuel costs more, the extra cost per mile or kilometre is (current price − base price) × fuel burned per unit distance, and fuel per distance is 1 ÷ mpg or L/100 km ÷ 100. Multiply by the trip distance for the surcharge on a run. Below the base price the figure is negative; whether that is a rebate or floored at zero is a contract term.
Percentage table
Many tariffs publish a table: for every step the fuel price rises above a base, the surcharge rises by a fixed percentage of the linehaul, often with a cap. The page applies that rule as written — ⌈difference ÷ step⌉ × percent per step — rounding up to the next full step, as tables usually do.
Parameters are contract terms
Base price, step, percent per step, cap and the fuel-price index used are all agreed between shipper and carrier; none is a constant and none is embedded. Enter yours from the contract or the carrier’s published rule. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- Per-distance rule: (current − base price) ÷ fuel economy; stepped percentage: ⌈Δprice ÷ step⌉ × % per step — both as written in carrier tariffs, with every parameter a user input
Last reviewed 20 September 2026. How results are checked: How we verify.