Calculate a trucking fuel surcharge per mile or as a percentage of linehaul from the current diesel price, your baseline fuel price, and truck MPG.
Fuel Surcharge Formula
FSC = (DP - BP) / MPG
TS = FSC * M
FSC% = (DP - BP) * S
- FSC is the fuel surcharge in dollars per mile
- DP is the current diesel price ($/gallon)
- BP is the baseline fuel price built into the base rate ($/gallon)
- MPG is the truck fuel economy used in the contract (typically 6)
- TS is the total surcharge for the trip ($)
- M is the trip distance in miles
- FSC% is the surcharge as a percentage of the linehaul charge
- S is the escalator, the percent added per $1.00 of diesel above the baseline (typically 15 to 25)
The per-mile mode uses the first formula: it subtracts your baseline from the current diesel price and divides by MPG to get the surcharge in dollars per mile. If you enter trip miles, it multiplies by the second formula to get the total surcharge, and adding a base rate returns the all-in rate and total invoice. The percentage mode uses the third formula, multiplying the price difference by the escalator to get a percent, then applying that percent to the linehaul charge if you enter one. The advanced fuel cost recovery option compares the surcharge you collect at the contract MPG against your extra fuel cost at your actual MPG, showing what share of the real cost increase the surcharge recovers. If the current price is at or below the baseline, the surcharge is zero in both modes.
Fuel Surcharge Rate Chart and Method Comparison
The chart below shows the per-mile surcharge at a $3.00 baseline and 6 MPG, the most common contract assumptions. At 6 MPG, the surcharge rises about 1 cent per mile for every 6 cent increase in diesel.
| Diesel price ($/gal) | Surcharge per mile | Surcharge on 500 miles |
|---|---|---|
| $3.00 or below | $0.00 | $0 |
| $3.25 | $0.042 | $21 |
| $3.50 | $0.083 | $42 |
| $3.75 | $0.125 | $63 |
| $4.00 | $0.167 | $83 |
| $4.25 | $0.208 | $104 |
| $4.50 | $0.250 | $125 |
| $4.75 | $0.292 | $146 |
| $5.00 | $0.333 | $167 |
The two calculation methods are used in different corners of the freight market. This comparison shows which one applies to your situation.
| Per-mile method | Percentage-of-linehaul method | |
|---|---|---|
| Common users | Truckload carriers, owner-operators, direct shipper contracts | LTL carriers, parcel carriers, some brokers |
| How it scales | With distance only, matching actual fuel burned | With the freight charge, so heavy or premium loads pay more |
| Key inputs | Diesel price, baseline, MPG | Diesel price, baseline, escalator, linehaul charge |
| Strength | Tracks the true extra fuel cost of the trip | Simple to apply across many small shipments |
| Weakness | Under-recovers if your real MPG is below the contract MPG | Surcharge changes when rates change, even if fuel does not |
Fuel Surcharge Example Problems
Example 1: Per-mile surcharge. Your contract sets a baseline of $3.00 per gallon at 6 MPG, and this week’s EIA average diesel price is $4.20. First, subtract the baseline from the current price: 4.20 – 3.00 = $1.20 per gallon. Next, divide by the MPG: 1.20 / 6 = $0.20 per mile. For a 500 mile load, the total surcharge is 0.20 * 500 = $100. If your base rate is $2.50 per mile, your all-in rate becomes $2.70 per mile and the invoice totals $1,350.
Example 2: Percentage-of-linehaul surcharge. A contract uses a $3.00 baseline with a 20% escalator per $1.00 increase, and diesel is currently $4.00. The difference is 4.00 – 3.00 = $1.00, so the surcharge percentage is 1.00 * 20 = 20%. On a linehaul charge of $1,800, the surcharge is 1,800 * 0.20 = $360, making the total charge $2,160.
Fuel Surcharge Frequently Asked Questions
Which diesel price should you use? Nearly all U.S. fuel surcharge contracts reference the Energy Information Administration (EIA) weekly on-highway diesel average, published every Monday. Contracts often specify a regional EIA index rather than the national number, so check whether yours uses the price for the region where the load originates. Update the surcharge each week when the new index posts.
Is a fuel surcharge required by law? No. There is no federal rule mandating a fuel surcharge; it is a negotiated term between the carrier and the shipper or broker. Brokers in the spot market usually pay one all-in rate with no separate surcharge line, so owner-operators booking spot freight should build the surcharge from this calculator into the rate they quote instead of expecting it as a separate payment.
Why does the surcharge not cover your whole fuel increase? The surcharge only offsets the price rise above the baseline, not your total fuel bill, and it assumes the contract MPG. If your truck gets 5.5 MPG while the contract assumes 6, you burn more gallons than the surcharge pays for. Use the actual MPG field in the advanced options to see your real recovery percentage, and negotiate a lower baseline or higher rate if it consistently falls short of 100%.
