Dimensional Weight—Everything You Need to Know for Accurate DIM Weighing

Pallets on shelves in a warehouse

In 2022, US business logistics costs (USBLC) totaled 1.85 trillion USD — approximately 8% of the nation’s GDP. Part of these expenses came from rising shipping expenses, as transportation costs for parcel carriers increased by 15.2%.

To curb these expenses, shippers no longer base their pricing on the actual weight of the parcels they carry — and they haven’t for some time. Dimensional weight has been used by parcel carriers since as early as 2007 as a way to base shipping rates on the volume of packages rather than their weight. Large, lightweight packages take up space and limit a carrier’s delivery capacity, driving up shipping costs for manufacturers.

Even if a particular supplier’s shipping rates are determined by dimensional weight, though, they can find ways to package their goods more efficiently, saving money both on shipping and production. To help with this, we’ve put together the following guide to show you how dimensioning systems work. Read on for more!

What Is Dimensional Weight (DIM)? 

Dimensional weight refers simply to the volume of a package divided by a factor unique to each shipper. It’s used to determine whether the cost of shipping a parcel should be based on its actual weight or on the space it occupies — your carrier will likely base your rates on whichever is larger. 

Why Is Dimensional Weight Used by Parcel Carriers?

Parcel carriers must handle a significant number of packages of different shapes and sizes: some of them are compact and heavy, while others are lightweight but large. 

The result of so many different parcel sizes is that shippers may be unable to maximize the capacity of each vehicle in their fleet. This increases transportation costs and manpower requirements, among other expenses, so sending products in unnecessarily large boxes is discouraged with higher fees. 

Modern-day carriers have found that basing their shipping rates on volume instead of weight may be a more accurate reflection of the true cost of getting your product from A to B. Dimensional weight gives that volume and converts it to an equivalent weight so that carriers can determine the actual expenses associated with shipping large, lightweight, or irregularly-shaped products. Such items are very common in the ecommerce industries that are so rapidly growing today, making it especially important for manufacturers in these segments to understand dimensional weight so that they can avoid being overcharged. 

How Do You Calculate DIM Weight?

Calculating dimensional weight is relatively straightforward, as it can be determined simply by finding the total volume of the package and dividing it by the Carrier’s Official Divisor, otherwise known as the DIM Factor. 

A DIM weight can be found with this simple equation:

Dimensional weight =  (Length X Width X Height)/(DIM Factor)

How to calculate dimensional weight

How to Calculate Dimensional Weight

A package’s dimensions can be found with ease, and the DIM Factor is often similarly easy to check. This number varies by shipper, but the DIM Factors for the three major parcel carriers are: 


      • FedEx: 139

      • UPS: 166

      • USPS: 166 (Parcels with dimensions under one cubic foot are not charged using dimensional weight.) 

    Because a larger denominator will result in a lower dimensional weight, suppliers may be able to save money by choosing the carrier with the lowest possible DIM Factor, assuming that all other rates, fees, and delivery times are equal. Choosing between daily or retail shipping rates can also impact DIM Factors, though, and suppliers sending their products overseas may calculate their dimensional weight in centimeters rather than inches, in which case the DIM Factor is 5,000 for all major parcel carriers.

    An Example of DIM Weight

    Suppose a manufacturer was shipping an electronic device that has an actual weight of 3 lbs. The device is 6 in. x 3 in. x 2 in. before packaging, but in an effort to keep the item safe during transport, it’s packed in a 12 in. x 12 in. x 6 in. parcel, complete with packing material. 

    Knowing that FedEx has a DIM Factor of 139, the supplier calculates that the dimensional weight of their device is (12 in. x 12 in. x 6 in.)/139, or 6.2 lbs. — more than twice the actual weight of the product. Similarly, the dimensional weight that UPS would charge is 5.2 lbs. USPS would not charge dimensional weight for a parcel of this size and would base their rate on the actual weight of the product — though packages weighing over 70 lbs. cannot be shipped.

    Armed with such knowledge, manufacturers can reduce their expenses by finding a carrier that can offer the lowest shipping rates while also designing their products and packaging systems to minimize costs. 

    How Dimensioning Systems Can Help

    iDimension LTL Pallet Dimensioning System showing a monitor with the dimensional weight


    iDimension LTL Pallet Dimensioning System

    Unfortunately, determining dimensional weight when shipping potentially millions of items per year can become a hindrance to production. That’s why suppliers need a dimensioning system. 

    Used to quickly determine the size of a product, dimensioning systems quickly provide carriers with the volume and weight of a parcel so that users can choose the proper freight class, reducing unnecessary shipping fees. Also known as dimensioners, these devices provide a number of benefits, like:


        • Speed. Measuring each pallet or package can cost valuable employee time, but dimensioners can measure an item in up to two seconds.

        • Accuracy. Human error is inevitable, and the dimensions of some parcels may not be so simple to calculate. Dimensioners can quickly and accurately measure flats, tubes, poly bags, and irregularly-shaped objects. 

        • Savings. The accuracy of dimensioning systems ensures that you’ll know the correct size of each product you ship, which means you’ll never pay too much for excess carrier fees.

        • Productivity. When your employees don’t have to take the time to size up your parcels, they’ll be freed up to complete more important tasks, making your team more productive. 

      Another benefit of using dimensional systems is the reduction in material waste.

      When manufacturers know how much more they’re paying for dimensional weight, they may change their packaging systems by using smaller boxes, different types of packing material, or redesigned products. Doing this can help cut back on both shipping and material costs while being environmentally friendly. 

      What Types of Dimensioners Are There?

      iDimension PWD Pallet Weighing and Dimensioning System getting the dimensional weight for a stack of packages


      iDimension PWD Pallet Weighing and Dimensioning System

      American Scale offers a wide selection of dimensioning systems. Designed to swiftly measure products ranging from small packages to industrial-sized freight, our dimensioners can meet the needs of most industries. Some of our most popular dimensioning systems are:


          • The iDimension® Plus Static Dimensioning System is built with smaller environments in mind. Particularly useful in the retail sector, this compact dimensioner requires no special alignment, includes a seven-inch touch screen monitor to display the package’s dimensions, image, and weight, and can size up a package in less than 0.2 seconds. 

          • The iDimension® PWD Pallet Weighing and Dimensioning System is engineered for dimensioning products of all shapes and sizes. Able to measure packages as small as six inches or large pallets of up to six feet cubed, this dimensioning system also features a tare function and a high-resolution camera to verify the condition of your freight. 

          • The iDimension® LTL Pallet Dimensioning System is an excellent way to improve quality assurance, designed for loading bays, warehouses, and shipping-and-receiving departments. Also available in an XL size, this dimensioner offers a Legal-for-Trade measurement range for items ranging from 12 in. X 12 in. X 12 in. up to 96 in. X 96 in. X 96 in., with a margin of error of 0.5 in. The overhead system also allows for 360° access, and its low-resolution intensity images can be configured to include product specifications. High-resolution imaging can also be added.

        We carry a host of other dimensioning system products as well, so whether you’re shipping small quantities of lightweight parcels or heavy-duty freight from the warehouse floor, you’ll never have to worry about excess shipping costs again. 

        American Scale Meets All Your Dimensioning System Needs

        At American Scale, we understand the impact that shipping costs can have on your bottom line. Our dimensioning systems can help you avoid overcharges and may save your operations valuable time and material. 

        Located in America’s heartland, we’re proud to deliver quality scale solutions for customers of all types of industries, so contact us today to see how we can help you.