When it comes to shipping packages, there's a crucial factor that every shipper must take into account: dimensional weight. This calculation method has been adopted by all major shipping carriers, including FedEx, UPS, and DHL, to ensure accurate pricing based on package size and weight. In this article, we'll cover everything you need to know about dimensional weight calculation, including its history, why it matters, formulas, and tools to make the process easier.

Understanding Dimensional Weight Calculation

Before we dive in, let's establish what we mean by "dimensional weight." Essentially, it's a way for shipping carriers to account for the amount of space a package takes up on their vehicles, as larger packages take up more room and limit the number of other packages the carrier can transport. Carriers use a formula to calculate dimensional weight, which we'll cover shortly, but it's important for shippers to understand why this calculation is necessary.

What is Dimensional Weight?

Put simply, dimensional weight is a calculation method used to determine the shipping cost of a package based on its size and weight. Shipping carriers established this method to prevent shippers from benefiting from the low cost of shipping lightweight but bulky items. By using dimensional weight, carriers ensure they are getting fair compensation for the space a package takes up in their vehicles, regardless of the weight.

Why Dimensional Weight Matters in Shipping

Dimensional weight matters for both shippers and carriers. For shippers, understanding the calculation method helps to ensure they are paying accurate shipping fees, as carriers charge based on the higher dimensional weight or actual weight, whichever is greater. Carriers benefit by maximizing the number of packages they can transport, which helps to keep shipping costs low for everyone.

The Difference Between Actual Weight and Dimensional Weight

To understand dimensional weight, it's important to distinguish it from actual weight. Actual weight is simply the weight of the package, while dimensional weight takes into account the package's size. The formula used to calculate dimensional weight considers the package's length, width, and height. We'll break down this formula in the next section.

How to Calculate Dimensional Weight

The formula used to calculate dimensional weight varies slightly depending on the shipping carrier, but the most common formula is:

Dimensional weight = (length x width x height) / dimensional factor

The dimensional factor is a number determined by the carrier, based on the size of their vehicles and the average density of packages they transport. For example, FedEx uses a dimensional factor of 139 for packages shipped within the US, while UPS uses a dimensional factor of 166.

Let's say you want to ship a package that is 20 inches long, 10 inches wide, and 8 inches high, and weighs 5 pounds. To determine the dimensional weight, you would first calculate the volume of the package:

20 x 10 x 8 = 1600 cubic inches

Then, you would divide the volume by the dimensional factor used by your shipping carrier:

1600 / 139 = 11.51

Since the dimensional weight is higher than the actual weight of 5 pounds, you would be charged based on the dimensional weight.

Tips for Reducing Dimensional Weight

Since dimensional weight can significantly increase shipping costs, it's important for shippers to take steps to reduce it whenever possible. Here are a few tips:

• Use smaller boxes or envelopes whenever possible

• Remove any unnecessary packaging or filler material

• Consider using a vacuum sealer to compress bulky items

• Choose a shipping carrier with a lower dimensional factor

By understanding dimensional weight and taking steps to reduce it, shippers can save money on shipping costs and ensure their packages arrive on time and in good condition.

The History of Dimensional Weight Calculation

The concept of dimensional weight calculation dates back to the early days of shipping, when carriers charged based solely on package weight. As shippers began shipping bulkier items that took up more room but weighed less, carriers realized they were losing money on these shipments. In 1991, UPS became the first carrier to introduce dimensional weight as a way to factor in package size when calculating shipping costs. Other carriers, including FedEx and DHL, soon followed suit.

Early Methods of Dimensional Weight Calculation

Before carriers adopted standardized dimensional weight formulas, they used various methods to calculate shipping fees based on package size. Some carriers used a "cubic inch" method, which involved multiplying the package's length, width, and height, while others used a "cubic pound" method, which used different conversion factors for different package sizes.

The Introduction of Dimensional Weight by Shipping Carriers

In 1991, UPS became the first carrier to introduce a standardized dimensional weight calculation method, using a formula that is still widely used today. Other carriers followed suit, which allowed shippers to compare shipping rates between carriers more accurately. As e-commerce grew in popularity, dimensional weight calculation became even more important, as online retailers frequently ship bulkier packages.

How Dimensional Weight Calculation Has Evolved

Over the years, carriers have refined their dimensional weight calculation methods to ensure they accurately account for package volume and are providing shippers with fair rates. For instance, carriers often adjust their dimensional weight divisor, which is the number used to divide the package volume to determine dimensional weight, to reflect changes in package sizes and densities. Additionally, carriers may use different formulas for international packages, which we'll cover later in the article.

Dimensional Weight Calculation Formulas

Now that we understand why dimensional weight calculation matters and how it has evolved, let's dive into the formulas carriers use to calculate dimensional weight. There are two primary formulas shippers should be aware of: the standard dimensional weight formula and carrier-specific formula.

The Standard Dimensional Weight Formula

The standard dimensional weight formula is used by most carriers, including UPS, FedEx, and DHL. It's a relatively simple formula that takes into account the package's length, width, and height in inches and divides that number by a set dimensional weight divisor of 139 for domestic packages or 166 for international packages.

Standard Dimensional Weight Formula: Length x Width x Height (inches) ÷ Dimensional Weight Divisor

For example, let's say you're shipping a package that measures 18" x 12" x 10" and weighs 5 pounds. To calculate the dimensional weight, you would use the following formula:

18 x 12 x 10 = 2,160 2,160 ÷ 139 = 15.53

In this case, the dimensional weight is 16 pounds, which exceeds the actual weight of the package. Thus, you would be charged shipping fees based on the higher dimensional weight.

Carrier-Specific Dimensional Weight Formulas

While most carriers use the standard dimensional weight formula, some carriers use a carrier-specific formula, which may incorporate additional factors. For instance, some carriers factor in the package's density, while others use different dimensional weight divisors for certain types of packages. Shippers should check with their specific carrier to understand which formulas are used and any adjustments they may need to make when calculating dimensional weight for that carrier.

International Dimensional Weight Calculation

When shipping internationally, shippers need to be aware of the dimensional weight divisor used by their carrier, as it may differ from the domestic divisor. Additionally, carriers may use different dimensional weight formulas for international packages, depending on the destination country and carrier partner. Shippers should check with their carrier or a shipping software solution that takes these variables into account for accurate international shipping rates.

Tools for Calculating Dimensional Weight

Calculating dimensional weight can be time-consuming, but fortunately, there are tools available to simplify the process.

Manual Dimensional Weight Calculation

For shippers who prefer to calculate dimensional weight manually, a measuring tape, ruler, and calculator are all that's needed. Simply take the measurements of the package, plug them into the dimensional weight formula, and calculate the result. Shippers should keep in mind that the process can be time-consuming and open to human error, particularly when shipping multiple packages with varying dimensions.

Online Dimensional Weight Calculators

For faster and more accurate calculations, shippers can use online dimensional weight calculators. These tools typically require inputting the package's dimensions and weight, as well as the destination and carrier, and generate shipping rates based on the carrier's dimensional weight formula. Some solutions also allow users to compare shipping rates between carriers for cost-saving benefits.

Shipping Software Solutions

Another option for simplifying dimensional weight calculation is to use a shipping software solution. These solutions take care of the calculation and rate shopping process, allowing shippers to compare rates and select the most cost-effective option. Shipping software solutions can also integrate with e-commerce platforms and other shipping systems for seamless management of the shipping process.

Conclusion

Dimensional weight calculation can be a complex and time-consuming process for shippers, but it's a necessary step for ensuring accurate shipping rates and maximizing the efficiency of shipping carriers. Understanding the history, formulas, and tools of dimensional weight calculation can help shippers navigate the process with ease and confidence, saving time and costs in the long run.