Owner-Operator Guide

How to Calculate a Fuel Surcharge

It's one line of arithmetic with three numbers in it. All three are negotiable, most drivers have never been told what theirs are, and each one moves real money on every mile you turn.

I've been driving since 1999. Local now; I ran brokered freight over the road before that. The fuel surcharge was a line I looked at for years without ever once checking whether it was right — I assumed it came out of a machine somewhere and that was that. It doesn't. It comes out of three assumptions somebody wrote down, and they can be asked about.

Why a surcharge exists at all

A line-haul rate gets negotiated once and then lives for months. Diesel doesn't sit still for months. The surcharge is the mechanism that lets the rate stay put while fuel moves underneath it — it floats up when diesel does and falls back when it drops. That is the whole idea. Whether it does that job properly for you comes down to the three numbers below.

The formula

( Current diesel price − Base price ) ÷ Assumed MPG = Surcharge per mile

Then: surcharge per mile × the miles it applies to = what the load should carry.

A worked example

Weekly diesel average: $3.85
Base price, or peg: $1.25
Assumed economy: 6.0 mpg
Load: 500 miles

$3.85 − $1.25 = $2.60 over the peg.
$2.60 ÷ 6.0 = $0.4333 per mile.
$0.4333 × 500 = $216.65 on that load.

Now change one input and watch what happens. Leave everything the same but assume 6.5 mpg instead of 6.0, and the surcharge falls to 40 cents a mile — $200 on the same load. Sixteen dollars and sixty-five cents, from one assumption nobody discussed with you. Run two thousand miles a week and that single number is worth roughly $67 a week, or somewhere north of $3,000 over a year of running.

That is the point of this page. Not that anyone is necessarily doing anything wrong — but that the assumptions are worth knowing, and they are worth asking about.

The four inputs, and which way each one cuts

The peg, or base price — The diesel price at which the surcharge starts. A LOWER peg means a BIGGER surcharge. Pegs set years ago and never revisited are common and they are worth asking about.
The reference price — Usually the EIA weekly on-highway diesel average, national or regional. Regional pricing matters if you run a high-cost lane.
The assumed MPG — The economy the formula pretends you get. A HIGHER assumed mpg means a SMALLER surcharge. Six is common. If the number in your agreement is 6.5 and your truck turns 5.8, the formula is quietly underpaying you on every mile.
Which miles it applies to — All miles, or loaded miles only. This one is easy to overlook and it changes the total more than people expect.

Where the price comes from

Most agreements point at the U.S. Energy Information Administration's weekly on-highway diesel average — the DOE or EIA number. It publishes every Monday and it's free to look up, which means you can always check the input yourself rather than taking it on faith.

Two details worth pinning down: national or regional (the Northeast and the West Coast run well above the national figure, so which one your agreement names is not a technicality), and which week applies — usually the prior week's publication, but it should say.

What a quarter on the peg is actually worth

“A lower peg means a bigger surcharge” is true and it is also too abstract to act on. So here is the arithmetic. The peg difference divided by the assumed mpg is the cents per mile it costs you. At 6 mpg over 100,000 miles:

Peg	Versus $1.25	Costs you	Per 100k miles
$1.25	The most commonly quoted starting point.	—	—
$1.30	5¢ higher than $1.25	0.8¢ / mile	about $833
$1.40	15¢ higher than $1.25	2.5¢ / mile	about $2,500
$1.50	25¢ higher than $1.25	4.2¢ / mile	about $4,167

Nothing here says a $1.50 peg is wrong. Pegs are a negotiated term and a higher one may sit alongside a better rate. The point is that a number people wave off as boilerplate is worth four thousand dollars a year at the top of that table, and it is worth knowing which one you signed before you decide it does not matter.

Tables instead of formulas

Plenty of brokers and shippers skip the arithmetic and publish a surcharge table instead — diesel between $3.80 and $3.899 pays this many cents a mile, and so on in small steps. It works the same way underneath, but the brackets round, and rounding is never random. If you're on a table, ask for a copy of it. You cannot check a surcharge against a table you have never seen.

If you're paid a percentage: the off-the-top question

This is the most-argued question in fuel surcharge and it has a cleaner answer than most people realise. If you are paid a percentage of the load, everything depends on which number the percentage is taken from. Say a load pays $2,000 linehaul plus $300 surcharge and you are on 70%:

70% of the total, $2,300 — you get $1,610.
70% of linehaul only, surcharge removed first — you get $1,400, and where the $300 went depends on what the agreement says.

Same load, same percentage, $210 apart. Example figures, for illustration.

Neither arrangement is automatically wrong. Both exist and both are legal. What matters is knowing which one you signed — and being able to see the load's actual breakdown rather than taking it on faith.

That second part is where most drivers stop, and they don't have to. Under the federal truth-in-leasing rules at 49 CFR 376.12(g), a lessor paid on a percentage basis is entitled to see a copy of the rated freight bill — or the equivalent document showing what the load was rated at. That is the piece of paper that answers the question. You are not asking a favour and you are not accusing anybody of anything. You are asking for a document the rules already say you can see, so that you can check your own percentage against it.

Six ways a surcharge comes up short

A stale peg — The base price was set in a different fuel era and nobody revisited it. Everything is calculated correctly on top of a number that no longer reflects anything.
An optimistic mpg — The assumed economy is better than your truck actually delivers. Perfectly legal, entirely negotiable, and it costs you on every single mile.
Loaded miles only — You deadheaded 120 miles to the pickup burning your own fuel and got surcharge on none of it.
The wrong week — Diesel moved and the settlement used a figure from a week that suits somebody else. Small each time. Not small over a quarter.
The line simply missing — It appears on three loads out of four. The fourth is not a policy decision, it is usually an oversight — and oversights get fixed when somebody points at them.
Rolled into an all-in rate — Nothing wrong with this if you knew. Everything wrong with it if you are judging the rate as though a surcharge is coming on top.

Checking your own, in five minutes

Find the surcharge terms in your lease or contract — the peg, the mpg, the reference price, and whether it's all miles or loaded only. If you can't find them, that is the first question to ask.
Look up the DOE weekly average for the week the load ran.
Do the arithmetic above. Write down what the load should have carried.
Compare it to the surcharge line on the settlement — and to the figure on the rate confirmation, which should match.
Do it for three or four loads, not one. One is an anecdote. Three of the same thing is a pattern, and a pattern is what gets a correction.

When you do make the call, you are not complaining. You are reading a number off their own paperwork and asking how it was arrived at. That is a completely different conversation, and it tends to go better.

Doing that check on one load is five minutes. Doing it on every load, every week, is a job. HaulProof reads your settlements, compares each load against what it should have paid, and flags the ones where the fuel surcharge, the miles or the detention don't line up — so a pattern shows itself while it's still recent enough to raise.

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Common questions

How do you calculate a fuel surcharge in trucking?

The standard method takes the current average diesel price, subtracts an agreed base price (the peg), and divides the difference by an assumed miles-per-gallon figure. That gives a surcharge per mile, which is then multiplied by the miles on the load. If diesel averages $3.85, the peg is $1.25 and the assumed economy is 6 mpg, the surcharge is $2.60 divided by 6, or about 43.3 cents a mile — roughly $217 on a 500-mile run. The three inputs are negotiable and every one of them changes what you get paid.

What fuel price is a surcharge based on?

Most contracts reference the U.S. Energy Information Administration's weekly on-highway diesel average, usually called the DOE or EIA average. It publishes every Monday, and agreements typically apply the figure from a set point — the prior week's national average, or a regional one. Regional matters: running the Northeast or the West Coast against a national average will read differently than running the Gulf. Check which one your agreement names.

Who keeps the fuel surcharge, the carrier or the driver?

That depends entirely on your agreement, and it is one of the most important lines in it. Some carriers pass the full surcharge through to the driver. Some pass a fixed portion. Some keep it and pay a flat all-in rate per mile instead. None of those is automatically wrong — what is wrong is not knowing which one you signed. Federal truth-in-leasing rules require the terms of a lease to be spelled out clearly, so it should be findable in writing.

Can the carrier take the fuel surcharge off the top before figuring my percentage?

If you are paid a percentage, this is the question that decides your pay, and the answer is in two places. First, the compensation clause in your lease — it should say whether your percentage is calculated on the total revenue for the load or on the linehaul with the surcharge removed first. Second, and this is the part most drivers never use: under the federal truth-in-leasing rules at 49 CFR 376.12(g), a lessor paid on a percentage basis is entitled to see a copy of the rated freight bill, or the equivalent document, for every load. That is the only document that shows what the load actually paid and how it was broken out. You do not have to argue about it — you can ask for it.

Why did my fuel surcharge drop this week when diesel did not?

Almost always the one-week lag. The DOE average publishes on Monday, and most agreements apply the figure from the previous week's publication rather than the price you are paying at the pump today. So your settlement is reflecting last week's diesel. When prices are falling, your surcharge keeps dropping for a week after the pump stops. When they are climbing, it lags upward the same way and the lag works in your favour. It only becomes a problem when the week used is not the week your agreement names — which is worth checking, because that is a different thing entirely.

Is a fuel surcharge paid on all miles or just loaded miles?

Both exist, and the difference is real money. A surcharge paid only on loaded miles ignores your deadhead — but you burned fuel getting there. Over a year with meaningful empty miles, loaded-only versus all-miles can be the difference between the surcharge covering your fuel and merely softening it. Find out which one applies to you and factor it into every rate you judge.

Why is my fuel surcharge different from the rate confirmation?

Common reasons: the peg or the mileage assumption changed and you were not told; the surcharge was calculated on loaded miles when you expected all miles; the load was paid at a flat all-in rate with no separate surcharge line; the week's DOE figure used was not the one you assumed; or the line was simply left off. One load off is worth a look. The same gap three weeks running is a pattern, and a pattern is something you can take to somebody with the paperwork in your hand.

The arithmetic is the easy part. The hard part is checking it against what actually landed on the settlement, week after week, when the DOE number moves every Monday. HaulProof reads the surcharge line on every settlement and flags the weeks it does not add up.

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Keep reading

This guide is general education for owner-operators and leased-on drivers — not legal, tax, or financial advice. The fuel prices, peg, mileage figures and totals in the worked examples are illustrative only; they are not current market rates, benchmarks, recommendations or industry averages, and the peg comparison table is arithmetic at a stated assumption, not a claim about what any particular agreement pays. The regulation referenced is at 49 CFR 376.12(g) and is summarised here in plain terms; it applies to leased-on owner-operators paid on a percentage basis. The text of the rule and, above all, the contract or lease you actually signed are what govern your situation — read it, and ask about anything you can't find. Built by a driver, for drivers.