How To Calculate Air Freight
Generally, the cost of your shipment is calculated based on the following factors:
- What does the shipment consist of? (the commodity)
- Where is it going? (the origin, destination and distance)
- How soon do you want it to get to the destination? (transit time)
- How heavy is the cargo? (the weight)
- How much space does the cargo occupy? (the volume)
In this article, we shall discuss the last two factors, which are the weight and volume of the shipment. When you plan for air freight transportation, you need to know how your shipment is weighed and therefore priced.
Your cargo is weighed based on multiple criteria. Your shipment’s chargeable weight could be based on either its gross or volumetric weight.
Gross Weight
Gross weight, also called actual weight, is the total weight of a shipment. It includes the net weight of the actual product coupled with the weight of the packaging.
On the other hand, the weight of only the product itself is called net weight. And the weight of only the packaging is called the tare weight.
There could be several instances in which the net weight and gross weight of cargo remain the same. For example, for car tires which are shipped without any packaging, both net and gross weights will be the same.
Gross Weight Calculation
Here’s the formula to calculate gross weight:
Product Weight + Packaging/Pallet Weight = Gross Weight
It is generally accepted that the actual weight of the cargo is measured using the metric system, e.g. kilograms and any imperial units such as pounds are converted into metric units for ease of calculation (1 kg = 2.205 lb). Let’s take a look at the example:
Product Weight + Packaging/Pallet Weight = Gross Weight
50 lb + 10 lb = 60 lb, converted to kilograms = 60 / 2.205 = 27.2155 kg
Volumetric Weight
The air freight volumetric weight, or dimensional weight, is an estimated weight value based on a package’s length, width and height. It is a theoretical weight calculated using a minimum air cubic conversion factor chosen by the freight carrier. This is generally stated as 6000 cm3 = 1 kg or 1 cbm (cubic metre) = 167 kg.
Volumetric Weight Calculation
To calculate the volumetric weight, there are a few steps. First, you need to calculate the volume of the shipment.
Length x Width x Height = Volume
Make sure that the volume is converted into cubic metres (m3 or cbm). If you are measuring the dimensions in inches, then you need to convert the volume from cubic inches to cbm (1 cbm = 61,024 cubic inches). And lastly, you need to do the air cubic conversion factor.
Here is an example of calculating the air freight volumetric weights if you measure the volume in cubic centimetres:
100 cm x 200 cm x 500 cm = 10,000,000 cm3
10,000,000 cm3 / 6000 = 1666.7 kg
Or, if you got the volume in cbm, here’s what it's like:
10,000,000 cm3 = 10 m3 or cbm
10 m3 x 167 = 1670 kg
You can also calculate the volume if the dimensions are in inches by using the formula:
Length x Width x Height/366
Here is another example of calculating the air freight volumetric weights if you measure the dimensions in inches:
10 inch x 20 inch x 50 inch = 10,000 inch3
10,000 inch3 / 366 = 27.3 kg
Difference Between Gross Weight and Volumetric Weight
You must be wondering why there’s a need to have two different measurements to calculate the airfreight chargeable weight of your shipment. It rests on the below principle.
Imagine two shipments of cotton and steel of similar weight. It is quite obvious that the cotton shipment will occupy more space than the steel shipment. The steel shipment, however, will weigh more. In such a scenario, should both shipments be charged by volume? Or should they be charged on the basis of weight?
Volumetric weight is significant to measure the space occupied by the shipment (volume or density). Whereas, gross weight is more focused on the weight of the shipment.
Chargeable Weight
Air freight chargeable weight is different from the volumetric or dimensional weight and gross weight. Rather, the chargeable weight is the quantified weight upon which the carrier charges you on the invoice, which can be either the gross or the volumetric weight of your shipment. In any situation, freight carriers would always choose the higher value between the volumetric and the actual weight of the cargo.
Let’s take a look at a measurement example. Here’s the known shipment measurement:
- Length: 50 cm
- Width: 25 cm
- Height: 70 cm
- Product weight: 18 kg
- Packaging weight: 2 kg
Let’s calculate the gross weight:
18 kg + 2 kg = 20 kg
Now let’s calculate the volumetric weight:
(50 cm x 25 cm x 70 cm) / 6000
= 87,500 cm3 / 6000 = 14.58 kg
Since the chargeable weight always uses the measurement with the greater value, in this situation we will use the gross weight, which is 20 kg. Next, you can check with the carrier or carrier’s agent for the price per kg and multiply it by your chargeable weight (20 kg) to get your total freight amount, excluding taxes and surcharges.