由 caicai8478 Okay, let’s delve deeper into the fundamental logic of logistics billing principles—why are there two calculation methods: actual weight and volumetric weight?
The core answer to this question can be summed up in one sentence: to strike a balance between the two limited transportation resources of “weight” and “volume,” ensuring fair and reasonable charges for the efficient use of transportation space.
Let’s break down this logic from several perspectives:
- Two Limitations of Transportation Vehicles
Any transportation vehicle (truck, ship, airplane) is subject to two physical limitations:
Weight Limit: The maximum weight that the vehicle, aircraft, or ship’s structure, engine, and chassis can withstand. Exceeding this limit can lead to mechanical failure and safety risks.
Volumetric Limit (Space Limit): The maximum available space within a cargo hold, container, or vehicle compartment. Exceeding this limit means that the cargo cannot physically fit.
The ideal operational state is to transport goods while simultaneously meeting both “full load” and “full volume.” This maximizes transportation resource utilization, minimizes unit costs, and maximizes returns.
II. Two Extreme Characteristics of Cargo
However, the characteristics of cargo in the real world vary greatly and can be broadly divided into two categories:
Heavy Goods / High-Density Goods:
Characteristics: High weight, but low volume (i.e., high density).
Examples: Metal parts, molds, books, machinery, tiles.
Impact on Transportation: This type of cargo may quickly reach the maximum load capacity of the transport vehicle, but the cargo hold is far from full. In this case, the limiting factor is weight.
Light Goods / Low-Density Goods / Bulky Goods:
Characteristics: High volume, but low weight (i.e., low density).
Examples: Down jackets, foam plastics, ping-pong balls, puffed food, plush toys in cartons.
Impact on Transportation: This type of cargo may quickly fill the maximum capacity of a transport vehicle, but its total weight is very light, far below the maximum load. In this case, the limiting factor is “space.”
III. Core Conflict and Business Logic
Charging solely by actual weight creates a significant business loophole and unfairness:
** Scenario A (Heavy Cargo):** Transporting a truckload of nails, weighing 10 tons, filling a full truck. Revenue is based on the 10-ton weight.
** Scenario B (Bulk Cargo):** Transporting a truckload of feathers, which is the same size as the truckload of nails (filling the truckload), but weighs only 100 kilograms. If charging solely by weight, revenue would only be the cost of 100 kilograms.
For the logistics company:
The costs of the two trips are virtually identical (same fuel consumption, driver wages, vehicle depreciation, and tolls, as both take up an entire truckload and one trip).
But the revenue is vastly different. The revenue from transporting feathers far fails to cover the costs, let alone generate a profit.
This is clearly unfair and unsustainable. Logistics companies cannot survive by transporting bulky cargo.
IV. Solution: Introducing Volumetric Weight
To resolve this contradiction, logistics geniuses came up with the ingenious billing tool called “volumetric weight.” Its underlying logic is:
Establish an equivalent exchange ratio between “weight” and “space.” The space occupied by the cargo is converted into an equivalent “weight value.” This converted value is then compared with the actual weight, with the greater value used as the billing weight.
For heavy cargo: Their actual weight is typically greater than their volumetric weight, so they are charged based on their actual weight. This makes sense because they consume more weight resources.
For bulky cargo: Their volumetric weight is typically greater than their actual weight, so they are charged based on their volumetric weight. This also makes sense because they consume more space resources.
The effect of this is:
Fairness: Regardless of the type of cargo you transport, as long as they consume the same amount of transportation resources (whether weight or space), you will pay roughly the same fee.
Economic Leverage: It encourages shippers to adopt more compact and efficient packaging methods. If a box can be packed smaller, thus reducing its volumetric weight, significant freight savings can be achieved.
Optimizing Loading: From a logistics company’s operational perspective, this charging method allows them to achieve reasonable returns for any cargo mix, enabling more rational network planning and pricing strategies.
Summary: A vivid analogy: You can think of a transport vehicle as a mobile warehouse.
Charging by actual weight: This is equivalent to charging rent based solely on the weight of the items you store. Someone storing gold (heavy cargo) pays a lot, while someone storing plastic foam (bulky cargo) pays little, yet they both occupy the same amount of shelf space (volume).
Charging by billable weight (the greater of actual weight and volumetric weight) is like a landlord setting a standard: “My shelf space is worth XXX yuan per cubic meter per month.” Whether you’re storing gold or plastic foam, as long as you occupy that amount of space, you pay the corresponding rent. This is fair.
Therefore, the coexistence of the two calculation methods is not redundant, but a sophisticated business design that accurately reflects transportation costs, maintains business fairness, and optimizes social logistics efficiency.