When we calculate a budget we take into account the actual weight, but it is also important to know the volume that the package will require. We need both data in order to perform the correct calculation of the budget and provide proper service. It will help us manage it properly, because we will know the kind of vehicle we will need when collecting the package. That is the reason why we calculate the volume weight. So you may be asking yourself: What is Volume Weight and how does it differ from the actual weight? When do you use one or the other? We answer these questions and we will explain you why for a carrier it is not the same to send a kilo of plumb than a kilo of straw.
Volume weight is the result of converting the volume of the package to kilos based on a conversion factor that is determined by the transport operator. First of all we calculate the volume, it is very easy, you get all the measures in meters and then you multiply them together. For example if we send a box of 40x40x60 cm 10 kg we have the following volume: 0,4 x 0,4 x0,6=0.096 m3. Then you just have to multiply this volume by the conversion rate.
Keep in mind that the conversion rate can vary as it depends on several factors such as pickup and delivery locations, transport vehicles, etc. Using the same example we will assume that it is a package that goes from Gijón to Dublin by land. In this case the conversion rate is 250kg/m3 and its real weight is 10kgs.
0.096m3 x 250kg/m3 = 24kg
Now that we know what is the volume weight and the real weight we can calculate the rate. We select the higher weight and we apply the price for the service and travel fee. In this case we see that there is an important difference between the actual weight (10 kg) and volume weight (24kg). This indicates that in this theory we are using a very large box for our 10 kilos, or that the content is very light but very bulky. It can also be a shipment that requires much protection as with shipments of computers, where the protections occupy much more volume than the computer, thought they are essential to ensure its safeness.
So, why do we apply the higher weight value? We do it this way because it is the most convenient for the expenses that will cause. We choose one or the other because although any transportation vehicle (van, cargo bike, truck, plane…) can carry a certain maximum weight, it also has a limited volume capacity. So when we have a large package we will need more space that can not be used for other packages.
And now we explain why sending 1kg of straw is more expensive than 1kg of plumb. 1kg of plumb has an aproximated volume of 0.00008m3 and 1kg straw, 0.006m3. So using the same Gijón-Dublin example above we get 0.02kg and 1.5kg. So 1kg of plumb weights the same as 1kg of straw but sending it will be 50% more expensive.
Our advice is to use the proper size of the boxes. We recommend a 60x40x40 box when sending personal items and a maximum weight of 25 kilos. It is the best weight/volume ratio you can get. Thought you should never neglect the safety and security of the content.