The Essential Guide to Cubic Weight Conversion.
When sending goods in Australia and across the world, there is a special formula used to calculate the chargeable weight. It can be quite confusing to understand how it all works, although let’s walk through it step-by-step so you get a thorough understanding of it.
Calculating the chargeable weight is based on two factors:
Whichever weight is the greater; dead weight or cubic weight will be used to calculate the freight charges, because as we all know, the basic carrier charges are calculated using a formula of (total weight in KG x distance from pick-up to delivery).
As a guide, the accepted standard volumetric rate in Australia is 1 cubic metre = 250 KG, although as we will see later on, this can alter depending on the mode of transport and service chosen.
What is 'dead weight'.
Cubic weight is a calculation that is used in shipping and freight to determine what you pay for goods being transported. The cubic weight formula was introduced by industry because it provided a more fair and accurate estimate of the cost of shipping than the traditional dead weight calculation. Dead weight is referred to as the actual weight of the item, regardless of how much space it takes up (volume).
What is 'cubic weight'.
The cubic weight (referred to as the volumetric weight) formula was introduced because it provided a more fair and accurate estimate of the cost of shipping, rather than just charging a price per KG.
Differences between 'dead' and 'cubic' weight.
The main difference between the two is that cubic weight takes into account the physical amount of space (volume) a package occupies on a truck, van, aircraft, container etc, while dead weight is the actual weight of the package.
For example, shipping a lightweight item such as feather pillows in a box with a volume of 0.4m3 and weighing 4KG will cost more per kilogram than shipping a 10KG crate of bricks with a a volume of 0.2m3. This is because the feathers take up more space on a truck (the volume is greater) for instance, relative to the actual weight of the bricks.
To explain it further, here is
This is important when shipping costs are calculated because shipments that are lighter yet have a larger volume, will often cost more to ship than those which are heavier yet take up less space.
Why should you care about 'cubic' versus 'dead' weight?
More often than not, the size of the box used to ship your goods determines the base cost of the freight.
When it’s time to pay your invoice, the total cost of shipping the goods could change because the shipment charges were calculated using the Cubic Conversion method.
Examples of how 'Cubic Weight' is charged instead of 'Dead Weight'.
NOTE: Although there are standard freight conversion factors in Australia, there are instances where some carriers may adopt their own formula.
Even though the accepted volumetric rate ratio in Australia is 1 cubic metre = 250 KG, the freight industry adopted a method of calculating cubic weight which took into account the different modes of transport.
- Air freight: 167
- Express freight: 250
- International Courier: 200
- General Freight: 333
- Sea Freight: 1000
Example 1 - General Freight
A box measuring 90cm long by 40cm wide and 15cm high, (90x40x15) and weights 7 KG is to be shipped via ‘general freight’ (ratio 333).
- To make it easier to calculate the volume of the box, let’s convert the measurements from centimetres to metres. We do this by adding a zero and a decimal point before each of the dimensions, which is written as 0.9 x 0.4 x 0.15 (LxWxH).
- Using the 0.9 x 0.4 x 0.15 calculation (multiplying the length x width x height of the box), the volume of box now equates to 0.054 cubic metres (m3).
- Now we have the volume in m3, it’s time to calculate the cubic weight using the ‘general freight’ conversion ratio of 333 (as seen in the table above). The formula to calculate the Cubic Weight of the box is (Cubic Volume) x (Cubic Conversion Rate), or (0.9 x 0.4 x 0.15) x 333.
- Using the above formula, the Total Cubic Weight is 17.98KG.
Not all Cubic Conversion Ratios are the same.
If customers were charged for the weight of each shipment, they could easily be overcharged for shipments which don’t weigh very much but take up a lot of space. Charging by cubic weight ensures that customers only pay for the actual amount of space (volume) the shipment occupies.
Be aware that different cubic conversion ratios exist across the freight industry and is dependent on which carrier, and service is used to deliver the freight.
Understanding how and invoice total can change.
Getting freight quotes from multiple carriers and showing the results on one screen is what we are well-know for throughout the industry. The total freight charge quoted may differ from the original quote because the weight of the item(s) has been re-calculated based on the cubic weight and not the actual weight ‘dead weight’ of the item.