Load factor answers one question about a vehicle: of everything it could carry on this trip, how much is it carrying? There are two versions. By weight, it compares the freight's weight with the vehicle's cargo weight limit. By volume, it compares the space the freight takes up with the space available, the measure also called cube utilization. A load that reaches its weight limit first "weighs out"; a load that fills the space first "cubes out."
How Do You Calculate Load Factor?
Divide the actual load by the available capacity, using the same unit for both, and multiply by 100. Use weight for dense freight and volume for light, bulky freight. If you are not sure which limit applies, calculate both.
Example, by volume: a trailer has 3,000 cubic feet of usable space, and the freight takes up 2,100 cubic feet. Load factor = 2,100 / 3,000 × 100 = 70%.
For a lane or a fleet over a period, add up what was carried and divide by the total capacity of the trips that ran. Example: three trips in trailers with 40,000 lb of cargo capacity carry 32,000, 24,000 and 40,000 lb. Load factor = 96,000 / 120,000 × 100 = 80%.
Weight or Volume: Which Limit Comes First?
Dense freight, such as beverages, paper, metal parts or machinery, tends to reach the weight limit while floor space is left over. Light, bulky freight, such as apparel, furniture, foam or empty packaging, tends to fill the space while the scale reads well under the limit. Freight density, the weight per cubic foot, tells you which way a load will go; the freight density calculator works it out from a pallet's dimensions and weight.
In the US, the weight side has a legal ceiling. On the Interstate System, federal rules generally cap gross vehicle weight at 80,000 pounds, or lower where the federal bridge formula requires it. That limit covers the tractor, the trailer and the cargo together, so the cargo a truck can carry is less than 80,000 pounds and depends on what the equipment weighs.
The volume side depends on the equipment too: the trailer or container's inside length, width and height, and how high the freight can be stacked without crushing it. Carton and pallet sizes decide how much of that space is usable; the pallet calculator shows how many cases fit on a pallet and how much of the pallet's cube they fill.
Load Factor vs. Cube Utilization vs. Fill Rate
- Cube utilization is load factor measured by volume: the share of a trailer's, container's or storage location's cubic space that is filled. A load can show a high load factor by weight and a low cube utilization at the same time.
- Fill rate measures service, not space: the share of ordered units or orders shipped from stock without a shortage. A warehouse can ship every order complete in trucks that run half empty.
- Load factor in aviation is measured over distance flown. US airline reporting rules define revenue passenger load factor as revenue passenger-miles expressed as a percentage of available seat-miles, and over-all revenue load factor, which counts passengers, freight and mail by weight, as revenue ton-miles as a percentage of available ton-miles.
- Load factor in electricity compares demand over time. The US Energy Information Administration defines it as the ratio of the average load to the peak load during a specified time interval.
Why Load Factor Matters in Shipping
When a carrier prices a full truckload by the trip, the shipper pays the same amount whether the trailer is 60% or 100% full. Every point of load factor therefore lowers the freight cost of each unit carried, and a low load factor means paying to move empty space. That is why shippers with enough volume for full truckload (FTL) watch it closely.
With less-than-truckload (LTL) shipping, a shipper's freight shares a trailer with other shippers' freight and is priced on its own weight, class and lane, so the carrier, not the shipper, works to fill the trailer. For ocean shipping, the same choice appears as a full container load versus a shared one, and load factor is how full the container is when the doors close.
How to Improve Load Factor
- Consolidate shipments. Freight consolidation combines orders bound for the same region or customer into one load instead of several partial ones.
- Plan the load. Load planning decides which pallets go on which trailer and where, and a transportation management system (TMS) can build loads from open orders automatically.
- Mix dense and light freight. Heavy freight on the floor with light freight stacked above lets one load approach both its weight and its volume limit.
- Cut empty space in cartons and on pallets. Packaging optimization right-sizes cartons, and consistent pallet patterns stack higher without overhang.
- Match the mode to the volume. When a shipment cannot fill a trailer, LTL lets the shipper pay for its share of a trailer instead of a whole truck that runs mostly empty.
A higher load factor is not always the cheaper choice overall. Holding orders until a trailer is full can delay deliveries, add storage time and break a delivery appointment, so shippers balance load factor against service and the cost of waiting.