How Are Freight Rates Calculated? The Per-Mile Math
A freight rate is linehaul + fuel surcharge + accessorials. Here's the per-mile math behind each layer, what moves lane rates week to week, and how brokers actually price a load.
A freight rate is the total price to move one shipment on one lane, built from three stacked layers: linehaul, fuel surcharge, and accessorials. Linehaul is usually quoted as a rate per mile, fuel floats with diesel, and accessorials cover anything beyond a plain dock-to-dock move.
That's the structure. Below is the math for each layer, what makes the same mileage price differently on two different lanes, and how a broker arrives at the number they send you.
The formula
For a truckload move, the arithmetic is straightforward:
(linehaul $/mile × loaded miles) + fuel surcharge + accessorials = all-in rate
Worked through with illustrative numbers — a 620-mile dry van load at a $2.15/mile linehaul, a $0.42/mile fuel surcharge, and one liftgate delivery:
| Layer | Math | Amount |
|---|---|---|
| Linehaul | 620 × $2.15 | $1,333.00 |
| Fuel surcharge | 620 × $0.42 | $260.40 |
| Liftgate accessorial | flat | $75.00 |
| All-in | $1,668.40 |
Divide back out and the load's effective all-in rate is $2.69 per mile. That all-in per-mile number is the only figure worth comparing between quotes, because a low linehaul with fuel and accessorials stripped out tells you nothing.
Those figures illustrate the structure — they are not a current market quote. Live linehaul benchmarks come from rate indices like DAT, and the fuel layer keys off the EIA weekly diesel price.
Layer 1: linehaul
Linehaul is the base: the cost to move the trailer from A to B, covering the driver's time, the equipment, and the miles. It's the biggest chunk of most rates and the layer most sensitive to supply and demand on your specific lane.
Truckload linehaul is quoted per mile. LTL works differently — it prices off freight class, weight, and distance from a carrier's rate base rather than a clean per-mile figure, which is why an LTL quote is much harder to sanity-check by hand.
Layer 2: fuel surcharge
The fuel surcharge sits on top of the linehaul as a separate line that floats with diesel, pegged to the published weekly national diesel average and a cents-per-mile table. When diesel climbs, the surcharge climbs with it even if your linehaul never moved. Carriers break it out so they aren't repricing every load every time fuel ticks up.
Full breakdown of how the tables work: what FSC means and how it's calculated.
Layer 3: accessorials
Accessorials are charges for anything beyond a simple dock-to-dock move:
- Liftgate — no dock, so the driver needs a powered gate to lower freight to the ground.
- Residential delivery — homes and non-commercial addresses cost more to service.
- Detention — when your dock holds the driver past the free loading window (often two hours), the clock starts billing.
- Limited access — schools, military bases, construction sites, farms: anywhere a driver fights to get in and out.
Accessorials are where cheap quotes turn expensive. A linehaul that looks great can balloon once a liftgate and a residential fee land on the invoice. A quote that bundles these in up front is worth more than a low number that doesn't.
What makes lane rates differ
Two lanes covering identical mileage routinely price hundreds of dollars apart. Three things explain almost all of it.
Headhaul vs. backhaul. A carrier prices the round trip, not your leg. A headhaul lane moves in the direction freight is already flowing, so trucks are plentiful and rates stay reasonable. A backhaul runs against the grain, and the carrier has to recover the cost of repositioning an empty trailer. Same miles, different economics.
Lane density. On high-volume corridors, plenty of trucks compete and rates stay tight. On a thin rural lane, fewer carriers means less competition and more leverage for whoever shows up.
Seasonality. Q4 retail peak pulls capacity from September through the holidays and rates climb. Produce season pulls reefer capacity hard in late spring and summer, and the spillover tightens dry van in growing regions. January slack is the opposite — volume drops, trucks sit, rates soften. If your freight is flexible on timing, those windows are real money.
Spot vs. contract rates
Contract rates are negotiated for a set period and a committed volume. They're stable and shield you from short-term swings, but you commit, and they lag the market in both directions.
Spot rates are priced load by load against whatever capacity exists today. Spot swings harder because it reflects the live market: when capacity tightens, spot spikes before contract catches up; when it loosens, spot falls first. If you ship irregularly or off-network, spot is where you live, which makes timing and competition matter more.
How brokers price loads
A broker doesn't invent a number. The process is:
- Price the lane. Pull recent paid rates on that origin-destination pair for that equipment type, from rate data and from what the broker's own carriers have recently accepted.
- Adjust for the load. Weight, equipment, appointment tightness, and lead time all move the number. A same-day load on a thin lane prices very differently from one with a week of notice.
- Add fuel and known accessorials. Anything the shipment will obviously need — liftgate, residential, tarps — gets priced in rather than surfacing on the invoice later.
- Put it to the carrier network. This is the step that actually sets the price. A load offered to one carrier gets that carrier's number. A load multiple vetted carriers can bid gets pushed toward the market floor.
- Quote the margin in. The broker's margin sits between what the shipper pays and what the carrier is paid. In a binding all-in quote, it's already inside the number you see.
That last point is the whole mechanism. We run your load against our vetted carrier network — each carrier CSA/FMCSA safety-checked and carrying at least $1M cargo and $1M auto liability coverage — and competition does the work on price. One number, all-in, fuel included, no surprise accessorials bolted on after the fact. Quotes bind in 60 seconds and lock for 48 hours.
FAQ
What is a freight rate?
A freight rate is the total price a carrier or broker charges to move one shipment between two points. It is built from a linehaul charge for the transportation itself, a fuel surcharge that floats with diesel prices, and accessorial charges for any service beyond a standard dock-to-dock pickup and delivery.
How are freight rates calculated?
For truckload, multiply the linehaul rate per mile by the loaded miles, add the fuel surcharge (usually cents per mile from a diesel index table), then add any accessorials. LTL is calculated differently, from freight class, weight, and distance rather than a per-mile figure.
What does freight rate per mile mean?
Rate per mile is the linehaul charge divided by loaded miles, which lets you compare loads of different lengths on the same basis. Always compare the all-in rate per mile with fuel and accessorials included, because a low linehaul per mile can hide a high total.
How do freight brokers price loads?
Brokers price from recent paid rates on the lane for that equipment type, adjust for weight, timing, and lead time, add fuel and expected accessorials, then offer the load to their carrier network. Competition among carriers sets the final number, and the broker's margin sits between the shipper rate and the carrier pay.
What are freight lane rates?
A lane rate is the going price for a specific origin-destination pair. Lanes with identical mileage can price very differently depending on whether freight flows that direction (headhaul versus backhaul), how many carriers run the corridor, and the season.
What is the difference between spot and contract freight rates?
Contract rates are locked for a period against committed volume and change slowly. Spot rates are priced per load against today's available capacity and move quickly in both directions. Spot leads the market and contract follows it.