Volumetric weight is a measure used by carriers to calculate shipping costs based on the volume of a package, rather than its actual weight.
This method addresses the issue of lightweight but bulky shipments.
To relate weight to volume, carriers use a Ratio expressed in cm3 / Kg or in Kg / m3. The commonly used ratio is 5000 cm3 / Kg.
For a package, you need to calculate the volume and divide it by the ratio, which gives us its volumetric weight, then simply take the greater value between its volumetric weight and its actual weight.
Don't worry... You don't have to do these calculations, the Advanced Shipping Cost Plus module does it brilliantly.
In the module, you can define volumetric weight in two ways. We will look at them together.
Method 1: With the Dimensions with volumetric weight condition
With this method, you will define the weight ranges of a carrier in the module rather than via the Carriers menu of PrestaShop.
Simply create a range at €0 for the concerned carrier in the Carriers menu.
- In the Conditions tab, select the Dimensions with volumetric weight condition
- Define the Ratio provided by your carrier (for example: 5000 cm3 / Kg)
- Add weight ranges with the corresponding amount
Details on the Rounding field:
Rounding = 1 → Rounds to the kilo (ex: 2.45 kg → 3 kg)
Rounding = 0.1 → Rounds to the nearest 100g (ex: 2.45 kg → 2.5 kg)
Rounding = 10 → Rounds to the nearest 10 Kg (ex: 2.45 kg → 10 kg)
Details on the Divider field:
Divider = 100 → Applies the defined amount every 100 kg
Method 2: With a formula
In this method, the weight ranges of a carrier will be configured in the Carriers menu of PrestaShop.
Add a rule in the Advanced Shipping Cost Plus module, then in the Actions tab, choose Weight, then enter the following formula: MAX((volume / 5000); weight)
After calculating the volumetric weight, the shipping cost retained will be that of the corresponding weight range, ensuring accurate billing.