KNOW YOUR COSTS
Fuel Surcharge Calculator
See what fuel really costs you after the surcharge you receive. Use your truck's actual MPG and every mile you drive, including travel that earns no surcharge.
What does fuel really cost you?
Enter the surcharge you actually receive and the fuel your truck uses. All amounts are in USD; fuel is measured in US gallons. Use the same trip or period for both mileage entries.
- Fuel used (US gallons)
- —
- Fuel bill (USD)
- —
- Surcharge received (USD)
- —
Enter your figures to see fuel cost after the surcharge.
This is a fuel-only calculation. A remaining fuel balance may be covered by the base freight rate; it does not by itself make the surcharge inadequate. A negative balance is a fuel-only surplus, before maintenance, wages, insurance and other costs—not total business profit.
The starting numbers are an illustrative example, not current market prices or a quoted offer.
Calculate a contract surcharge
Use this simple peg-based method if it matches your agreement. The contract/reference MPG sets this formula; changing your truck's actual MPG does not automatically change the payment.
Enter the contract figures to see the surcharge.
Surcharge per mile = (reference diesel price − base/peg) ÷ contract MPG, floored at $0. Reference gallons = eligible contract miles ÷ contract MPG; this is not measured fuel consumption. Totals use the unrounded per-mile result. Your agreement may use a different schedule or rounding rule.
Starting figures are illustrative, not market data. If your agreement uses an EIA index, find its specified series and date in the EIA Gasoline and Diesel Fuel Update.
What a fuel surcharge covers
A fuel surcharge (FSC) is a fuel-related payment added to the basic freight payment, often called linehaul. The agreement determines the surcharge, the miles that qualify and any price reference. A base or peg price is the fuel price already assumed in the base freight rate. A peg-based surcharge can cover the increase above that price rather than the entire fuel bill.
Your actual MPG tells you how much fuel the truck uses. The contract/reference MPG is an assumption used in a surcharge formula. Keeping these separate lets you see what better fuel economy does for your own costs, even when the agreed surcharge stays the same.
How fuel cost after surcharge is calculated
- Gallons used = total miles actually driven ÷ actual MPG.
- Fuel bill = gallons used × actual pump price.
- Surcharge receipts = surcharge-eligible miles × received surcharge per mile.
- Remaining fuel cost = fuel bill − surcharge receipts.
- Effective fuel cost per gallon = remaining fuel cost ÷ gallons used.
Effective cost is the fuel expense left after the surcharge, spread over the gallons used. It does not change what you paid at the pump. A negative result is a fuel-only surplus. If no gallons are used, a per-gallon result is undefined.
The shorter formula, pump price − (surcharge per mile × actual MPG), works only when every driven mile earns that surcharge and eligible miles equal driven miles. Empty travel, or deadhead, burns fuel and may earn no surcharge. Contract mileage can also differ from actual distance, so the calculator keeps both mileage entries independent.
Same surcharge. Different fuel costs.
| Actual MPG | Driven miles | Fuel bill | Surcharge | Fuel balance | Effective / gallon |
|---|---|---|---|---|---|
| 6 | 1,000 | $750.00 | $500.00 | $250.00 expense | $1.50 |
| 8 | 1,000 | $562.50 | $500.00 | $62.50 expense | $0.50 |
| 10 | 1,000 | $450.00 | $500.00 | $50.00 fuel-only surplus | −$0.50 |
| 8 | 1,100 | $618.75 | $500.00 | $118.75 expense | $0.86 |
With the same 1,000 driven miles, the 8 MPG truck spends $187.50 less on fuel than the 6 MPG truck. Add 100 uncovered miles at 8 MPG and the fuel balance rises from $62.50 to $118.75. Other operating costs are outside this comparison.
Frequently asked questions
What is a fuel surcharge?
A fuel surcharge is a fuel-related payment added to the basic freight payment. The contract determines its rate and eligible miles. A peg-based surcharge may cover only the increase above the fuel price already assumed in the base freight rate.
Does better actual MPG change my contracted surcharge?
Not automatically. The agreement sets the surcharge formula and any reference MPG. Better actual MPG reduces the gallons your truck burns. With the same pump price, driven miles and surcharge payment, that leaves less fuel expense to cover.
How do I calculate fuel cost after the surcharge?
Divide total driven miles by actual MPG to find gallons used, then multiply by the pump price. Subtract surcharge receipts, calculated as eligible miles times the received surcharge per mile. Divide that remaining fuel cost by gallons used for the effective fuel cost per gallon.
Why enter eligible miles and driven miles separately?
Surcharge-eligible miles are the miles the agreement pays on. Driven miles are the actual distance traveled, including empty travel, detours and other uncovered miles. Contract mileage can differ from the distance actually driven; use the records for the same trip or period.
What does a negative fuel cost mean?
A negative remaining cost is a fuel-only surplus: the surcharge exceeds the modeled fuel bill. It is not total business profit. Other costs still have to be paid.
How does the peg-based calculator work?
For this simple reference method, subtract the contract base or peg price from the reference diesel price, divide by the contract/reference MPG, and floor the surcharge at zero. Multiply by surcharge-eligible miles for the payment. The actual contract may use a different schedule, rounding rule or price reference.
Methodology & sources
Calculations use the inputs above, without intermediate rounding. Displayed amounts are rounded to cents and gallons to two decimal places. Actual fuel consumption, payment terms and records determine your final result. The evaluator models fuel used as miles divided by average MPG; use an MPG that reflects fuel consumed over the same period.
Sources checked October 24, 2026: OOIDA fuel surcharge calculator and explanation; U.S. EIA Gasoline and Diesel Fuel Update. The EIA publishes fuel-price references; it does not set your surcharge agreement. All defaults and worked examples here are illustrative USD amounts per US gallon, not refreshed market data. Updated October 24, 2026. Built by TruckMargin.