Have you ever packed a suitcase too full, only to find that you couldn’t zip it completely because it of the overloaded contents? A similar scenario happens to shipping carriers transporting your customer orders. Whether by plane, train, automobile, truck, or shipping container, every type of carrier transportation has a capacity limit.

Regardless of the shipping method, all carriers have developed packing strategies that are designed to maximize their capacity and their revenue. Because of this, shipping carriers use a technique to measure volumetric weight (also known as dimensional weight) in order to increase efficiency. Instead of solely calculating price based on weight, carriers use volumetric weight to charge more for lightweight items that occupy more space.

In this article, you’ll learn everything you need to know about volumetric weight, how carriers calculate it, and how you can reduce or avoid extra fees. 

What is volumetric weight?

Volumetric weight, or dimensional weight, is a theoretical figure based on the weight and dimensions of the parcel being shipped. The volumetric weight can exceed the actual physical weight of the package, since it factors in the amount of space a parcel will take up in the delivery process, such as a truck or a plane.

The purpose of measuring volumetric weight is so that shipping carriers can ensure they don’t take a financial hit when people ship large, lightweight parcels. Thus, it costs more to ship items that are large and light, such as pillows or stuffed animals.

Historically, shipping costs were calculated based on gross weight. However, this meant that lightweight, low density packages were unprofitable for freight carriers to transport. The large amount of space the packages take up in the ship, truck, or aircraft is not economical in proportion to their actual physical weight.

This caused the worldwide transportation industry to adopt the concept of volumetric weight as a standard means of setting a minimum cost based on the cubic space a package occupies. In 2015, UPS and FedEx began implementing charges on all shipments (via air and ground) based on the greater of the actual weight and dimensional weight of a package. Before that, dimensional weight charges only applied to packages of a specific size range.

Ultimately, it would cost you more to ship a plane full of feather pillows than it would to ship a plane full of smartphones. Because the pillows take up more space and they have lower profit margins, you would need to ship a larger volume to make an exciting profit.

Physical weight is the weight of the parcel according to the scale.

Volumetric weight is calculated using a formula that establishes the volume weight of a package based on the dimensions of the box. First, it is calculated based on the package’s length, width, and height.

Next, it is divided by the volumetric divisor. The volumetric divisor is a predetermined number that varies based on (1) the country and (2) the freight forwarder.

Thus, in terms of volumetric weight, a large box of feather pillows could be considered heavier than a smaller box full of smartphones. Another way to visual this is that a 5 pound laptop is lighter than a 5 pound bag of cotton in terms of dimensional weight.

Although they have identical physical weights, the cotton would take up far more space than the laptop. Since the volumetric weight of the pillow is higher than the physical weight, the shipping carrier will charge fees based on what will make them more money – the volumetric weight of the package. This is especially important for hopeful Amazon sellers to understand when considering selling products with FBA.

How is volumetric weight calculated?

Volumetric weight is calculated by measuring the length, width, and height of the ready-to-mail package. Multiply the measurements together (L*W*H) to obtain the sum, which is the cubic size of your package.

For example:

  1. Your parcel measures 40 inches x 16 inches x 16 inches.
  2. We multiply the three dimensions – 40 inches, times 16 inches, times 16 inches – which equals a total of 10,240 cubic inches (the cubic size).
  3. Most shippings carriers – such as FedEx, UPS, and DHL Express – will divide the cubic size of the package using 139 as the dim factor (or volumetric divisor) for domestic and international shipments to achieve the final volumetric weight in pounds. (Some exceptions are FedEx SmartPost and DHL, which use 166 as the dim factor for international shipments.)

If that parcel is shipping to a domestic address, its volumetric weight would be 10,240 divided by 139, which equals 73.67 pounds.

Always round up the results when making calculations. For example, if the length of the package is 22.25, round up to 23.

Note: To determine volumetric weight in kilograms, the formula is (L*W*H/6000) for domestic shipments and (L*W*H/5000) for international shipments.

How can volumetric weight be avoided or reduced?

Dimensional weight favors shipments of dense objects and penalizes shipments of lightweight boxes. It can be reduced or avoided by making your package as economical as possible.

Ensure you are using the smallest box suitable for shipping your items safely. If you work with a great fulfillment company, they should be able to help you manage fulfillment costs by providing packaging services that maximize efficiency and minimize shipping costs.

Sometimes this is done by reducing the use of packing materials. For example, by removing a product from its original packaging, then re-packing it in a way that betters conforms to the shipping parcel.

Another option is to choose a service that uses a higher volumetric divisor, which would lower your volumetric weight according to that carrier’s fees.

It’s important to note that it’s necessary for shipping carriers to charge based on volumetric weight because it allows freight companies to produce a better service while maximizing scarce resources such as gas. Volumetric weight ensures that sellers are fairly charged for shipping large but very light items that take up more space in the limited capacity of a transportation method.