When it comes to parcel delivery, you may encounter a situation where your package weighing 5kg is billed as 10kg. This is because logistics companies compare the volumetric weight (calculated based on size) with the actual weight and charge based on the larger one. It’s crucial to understand volumetric weight calculations to manage freight costs effectively.

 

What is the Dimension Weight?

 

Dimensional weight (also known as volumetric weight) is a pricing technique used by shipping companies to calculate the cost of shipping based on the size (volume) of a package rather than its actual weight. This method helps carriers account for the space that a package takes up in transport, particularly when dealing with large but lightweight packages.

 

Why Dimensional Weight is Important?

1.Space Efficiency: Shipping companies want to maximize their cargo space. If a package is large but light, it still takes up valuable space in the shipping vehicle or aircraft. By charging based on dimensional weight, carriers ensure they are compensated for this space usage.

 

2.Fair Pricing: For bulky but light items, dimensional weight ensures that shipping costs reflect the actual space consumed during transportation, rather than just the weight of the package

 

Difference between dimensional weight and actual weight.

Actual Weight vs Dimensional Weight

Aspect Actual Weight Dimensional Weight
Definition The real weight of the package measured on a scale. A calculated weight based on the size of the package.
Basis of Calculation Measured directly using a scale. Based on the dimensions (length, width, height) of the package.
Use Directly used when the package is dense (heavy). Used for large but lightweight packages (bulky items).
Impact on Shipping Cost Typically used when the weight is greater than the dimensional weight. Used when the dimensional weight is higher than the actual weight.
Example A package weighs 5 kg. A large box with a dimensional weight of 7 kg (even if it weighs only 4 kg).

 

How to calculate volumetric weight?

 

To calculate volumetric weight (also known as dimensional weight), you’ll need the dimensions of the package and the divisor used by the shipping carrier. Volumetric weight helps shipping companies determine how much space a package takes up in relation to its actual weight.

 

Formula for Volumetric Weight: Length×Width×Height/Divisor

 

Shipping mode Formula DIM Factor)
Air (L × W × H in cm) ÷ 6000 166
Express (L × W × H in cm) ÷ 5000 200

 

SEA：The different CBM to KG conversion factors are used based on the type of cargo and shipping method. Here’s what each ratio typically applies to:

Common CBM to KG Conversion Factors：

1 CBM = 1000 KG Standard LCL (Less than Container Load) Sea Freight
1 CBM = 750 KG Heavy Cargo in Sea Freight (e.g., steel, machinery)
1 CBM = 500 KG Light to Medium Cargo in Sea Freight
1 CBM = 363 KG Some Air Freight Carriers’ Volumetric Weight Rule

 

An Live Example to calculate shipping cost

Let’s walk through a live example to calculate the dimensional weight (DIM weight) and freight charges for courier/air, express and sea shipments.

Example Shipment:

Package Dimensions: 40*50*60cm   Actual weight: 8kg  8 cartons

Shipping cost: 8USD/kg

 

There are 4 steps:

  1. Calculate the total weight
  2. Measure the dimensions and calcualte the dimensional weight
  3. Compare the actual weight and dimensional weight
  4. Calculate the shipping cost

 

If ship by express:

  1. The actual weight is : 8*8=64kg
  2. The DIM weight is:40*50*60/5000*8=192kg / Or

（40*50*60）*8/1000000=0.96CBM, 1CBM=200kg, 0.096*200=192kg

  1. Actual weight 64kg<DIM weight 192kg
  2. The shipping cost is: 192*8USD=1536USD

 

If ship by Air:

  1. The actual weight is : 8*8=64kg
  2. The DIM weight is:40*50*60/6000*8=160kg / Or

（40*50*60）*8/1000000=0.96CBM 1CBM=167kg, 0.096*167=160kg

  1. Actual weight 64kg<DIM weight 160kg
  2. The shipping cost is: 160*8USD=1280USD

 

Note:

In practice, you might hear that freight forwarders will combine lightweight and heavy parcels into one air shipment to make full use of the space and make more profits.

 

Suppose that a freight forwarder has booked a space and collected a lot of heavy products, and you have a batch of big-sized but light-weighted products to ship. At this time, the forwarder will be very willing to ship your products together with his heavy goods in the same shipment.

 

Common ratios: 50%/50%, 20%/80%, 30%*70%

The calculation formula is as follows:

Final chargeable weight = Actual weight + [(DIM weight – actual weight) x percentage]

= [64+（160-64)x50%]=112kg

Final shipping cost =Final chargeable weight*Unit price

=112*8USD=896USD

Can it be transported in this way? Please consult the transportation company.

 

If Ship by Sea:

1.The actual weight is : 8*8=64kg

  1. The DIM weight is:40*50*60/6000*8=160kg / Or

（40*50*60）*8/1000000=0.96CBM 1CBM=1000kg, 0.096*1000=96kg

  1. 3. Actual weight 64kg<DIM weight 96kg
  2. The shipping cost is: 96*8USD=768USD

 

Note: if the regular carton swells and bulges due to cargo extrusion, as shown in the below image, it shall be calculated according to the longest side of the carton.

 

 

How to reduce dimensional weight to save money?

 

To reduce dimensional weight (DIM weight) in shipping, you can focus on minimizing the size of the package, ensuring it is as compact and efficient as possible. Here are several strategies to reduce DIM weight:

 

  1. Use Smaller Packaging

Select the right box size: Choose a box that fits the product snugly, without excess empty space. Using larger boxes than necessary increases the volume and thus the DIM weight

  1. Optimize Packing Materials
  • Use lightweight packing materials: If you need padding or cushioning, opt for lightweight materials like bubble wrap or air pillows, which protect the item without adding significant weight or volume.
  • Use fewer packing materials: Try to pack efficiently to reduce the overall size and weight. Avoid excessive fillers that increase the size of the package
  1. Consolidate Shipments

Group smaller items: If you’re shipping multiple small packages, consider consolidating them into one larger package. This can help optimize the total volume, lowering the average DIM weight across shipments.

 

The End

Thank you for reading! We hope this has helped you better understand DIM weight and its impact on shipping costs. If you have any questions, feel free to leave a comment below.

At Dropshipme, we’ve been helping customers source, pack and ship products for 10 years. Bulk products to customers or dropship to custmers one by one are supportable. Let us know your needs and enjoy the service.