由 caicai8478 Okay, let’s uncover the logic behind the mysterious numbers “200” and “167” in logistics calculations. This is absolutely key to understanding volumetric weight billing.
Core Conclusion First
“200” and “167” are essentially two different expressions of the same conversion relationship. They both define the core principle of “1 cubic meter (CBM) of volumetric space is equivalent to x kilograms of billable weight.”
167 kg/m³ is a common standard for international air freight and express delivery (such as DHL, FedEx, and UPS).
200 kg/m³ is a common standard for domestic land transportation (such as trucking) and some ocean freight in China.
The difference in conversion factors (Volumetric Divisor) is simply due to differences in industry and transportation modes.
I. Derivation Process: Where Do the Numbers Come From? To understand these two numbers, we must return to the basic formula for volumetric weight:
Volumetric weight = length × width × height / conversion factor
The purpose of this formula is to determine a “virtual weight” that can be compared to the “actual weight.”
- The Origin of “167” (Air Freight/International Express Standards)
Step 1: Establishing the Standard
The International Air Transport Association (IATA) and other organizations stipulate that 1 cubic meter (m³) of volumetric space is equivalent to 167 kilograms (kg) of billable weight.
This is an industry-recognized “weight-space” value equivalence standard.
Step 2: Converting to a Calculation Formula
We know: 1 cubic meter = 100 cm * 100 cm * 100 cm = 1,000,000 cubic centimeters (cm³).
According to the standard: 1,000,000 cm³ ≈ 167 kg.
So, how many cubic centimeters should 1 kg of volumetric weight correspond to?
Conversion Factor = Volume / Weight = 1,000,000 cm³ / 167 kg ≈ 6000 cm³/kg
Conclusion:
Therefore, the standard calculation formula for air freight is:
Volumetric Weight (kg) = Length (cm) × Width (cm) × Height (cm) / 6000
Using the factor of 6000, this ultimately means 1 CBM = 167 kg.
- The Origin of “200” (Domestic Land Transport Standard)
Step 1: Establishing the Standard
In domestic road transport (truck) in China, the industry practice is that 1 cubic meter (m³) of volumetric space is equivalent to 200 kilograms (kg) of billable weight.
This is a “weight-space” value equivalence standard established in the Chinese market and applicable to land transport.
Step 2: Converting to a calculation formula
In China, people are more accustomed to using “meters” for calculations. The formula is: Volumetric Weight (kg) = Length (m) × Width (m) × Height (m) × Conversion Factor
According to the standard: 1 m³ = 200 kg
So, the “conversion factor” is 200.
Conclusion:
Therefore, the common calculation formula for domestic land transportation is:
Volumetric Weight (kg) = Length (m) × Width (m) × Height (m) × 200
Using the multiplier of 200, we directly define 1 CBM = 200 kg.
II. Why are the standards different? — “The Secret of 200 and 167”
The secret lies in: the cost structures of different transportation methods are completely different.
Transportation Method Core Cost Drivers Why the Coefficients Are Different (Why the “Price” of 1 CBM Is Different)
Air Transport (167 kg/CBM) Time, Space, Fuel
Aircraft operating costs are extremely high (fuel, airport landing fees, maintenance), and cargo space is extremely valuable and limited. Air transport has the highest “spatial opportunity cost.” If a cubic meter of space can be used to transport high-value cargo, it can generate extremely high profits for airlines. Therefore, they penalize “light cargo” that takes up space more harshly. The 167kg/CBM standard makes it easier for the volumetric weight to exceed the actual weight, resulting in higher charges. A smaller coefficient (6000) results in higher charges.
Land Transport (200kg/CBM): Weight, Distance, and Tolls
Truck fuel consumption, tire wear, and tolls are more closely correlated with weight. Truck space is less valuable than air freight. Land transport is more sensitive to weight than space. Trucks hauling heavier cargo experience significantly higher fuel costs. Therefore, they are more sensitive to “heavy cargo.” For “light cargo,” the standard is less stringent. The 200kg/CBM standard requires a larger volumetric weight to exceed the actual weight. A larger coefficient (equivalent to 5000 cm³/kg, *¹) results in more lenient charges. *¹ Note: If multiples of 200 for land transport are also expressed in centimeters, the conversion factor is 1,000,000 cm³ / 200 kg = 5,000 cm³/kg. Therefore, you may find that some express delivery companies (such as SF Express) may also use the /5000 rule for land transport, which is equivalent to ×200. *
III. Practical Comparison: Same Cargo, Different Destinies
Suppose there is a lightweight cargo: 1m x 1m x 1m (exactly 1 CBM), with an actual weight of 100kg.
Transportation Method Calculation Standard Volumetric Weight Calculation Chargeable Weight Result Analysis
Air Freight: 1 CBM = 167kg 100x100x100 / 6000 = 167kg 167kg (whichever is greater) Actual weight is 100kg, but it is charged as 167kg because it takes up valuable space on the aircraft.
For land transport, 1 CBM = 200 kg. 1 x 1 x 1 x 200 = 200 kg. 200 kg (whichever is greater) Actual weight is 100 kg, but the charge is 200 kg.
(Comparison) If it is a heavy cargo,
Actual weight is 250 kg. Air freight: 167 kg
Land transport: 200 kg. 250 kg (whichever is greater) Because the actual weight is greater, both are charged as 250 kg. Costs are primarily determined by weight.
From this example, does it appear that for the same lightweight cargo, the air freight chargeable weight (167 kg) is lower than the land freight chargeable weight (200 kg)? Wrong! Wait! 1 CBM of space is calculated as 167 kg for air freight and 200 kg for land freight. Doesn’t that mean air freight is cheaper?
This is a key misunderstanding! Never directly compare these two figures to determine freight costs. This is because:
The unit price of air freight (yuan/kg) is much higher than the unit price of land freight (yuan/kg).
Although 1 CBM for air freight only counts as 167kg, the per-kg freight rate might be 30 yuan. For land freight, 1 CBM counts as 200kg, but the per-kg freight rate might be only 3 yuan.
The final total freight cost for air freight might be 167kg * 30 yuan = 5,010 yuan; for land freight, it might be 200kg * 3 yuan = 600 yuan. Air freight is still significantly more expensive.
The “167” and “200” numbers define how space is converted to weight, not the final price.
In summary, the “200” and “167” numbers serve as a bridge between volumetric weight and cubic meters (CBM), defining “how many kilograms is one cubic meter of space worth.”
200 is commonly used for domestic land transport, derived from the formula: Volumetric Weight = Length (m) * Width (m) * Height (m) * 200.
167 is commonly used for international air transport/express delivery, derived from the formula: Volumetric Weight = Length (cm) * Width (cm) * Height (cm) / 6000.
Root of the difference: Air and land transport have completely different cost structures. Air transport penalizes space (with a strict coefficient), while land transport penalizes weight (with a loose coefficient).
Key Reminder: Never directly compare the prices of different shipping methods based on the size of 167 and 200. The total cost must be calculated based on the unit price per kilogram.