What is Dimensional Weight and Why Does it Matter?

It seems like a simple concept: your package weighs a specific amount, so your shipping rates should reflect that, right? Unfortunately, it doesn't always work that way in the small package world. Shippers also need to account for something called dimensional weight (also known as DIM weight) when calculating costs.

We've put together some FAQs to make sure your business understands the importance of DIM weight.

What is DIM weight?

DIM weight refers to how dense a package is, or the amount of space a package occupies relative to its actual weight. The classic example of a low weight, high volume shipment is a box of ping pong balls — they take up a disproportionate amount of space for their weight.

The key thing to know about DIM weight is that the actual billable weight of your package will be the greater of the dimensional weight or the actual weight. That makes it crucial to accurately calculate it to ensure an accurate small package shipping rate. DIM weight applies to all UPS domestic and international services, as well as those of other small package carriers. UPS has set standard size and weight limits, and does not accept packages that exceed these limits without applying an Over Maximum Limit charge.

Why does UPS small package shipping rely on dimensional weight?

Applying rates based on DIM weight allows carriers to better optimize the use of their vehicles, fuel and other resources. If a package takes up a large amount of room in a plane, feeder truck or package car, it costs more for the carrier to ship that item even if it doesn’t weigh that much.

DIM weight is all about container size and what can fit on a conveyor belt in the UPS system. Anything that is difficult to move on a belt, such as long boxes, tubes and similar packages, will incur an additional cost.

How do I calculate DIM weight?

Fortunately, calculating the dimensional weight of your package is pretty straightforward. Here are the steps:

  1. Determine the actual weight. Use any standard scale to determine the actual weight of your package.
  2. Determine the dimensional weight. To determine it in pounds, divide the cubic size of your package in inches (the product of multiplying your package's length x width x height) by 139. Round up any fraction to the next whole pound. To calculate it in kilograms, divide the cubic size of your package in centimeters by 5,000. Round up any fraction to the next whole kilogram.
  3. Determine the billable weight. Compare each package's actual weight to its dimensional weight. The larger of the two weights is the billable weight and should be used to calculate the shipping rate.

How can I minimize dimensional weight charges?

We hear you. You don't want to pay more for your small package shipping than necessary. To minimize your DIM weight charges, carefully consider the size of the box that your package will be shipped in. Just decreasing the size of a package by a couple of square inches or packing it into a more standard-shaped box, can dramatically decrease the charges that could be assessed. A right-sized container could mean big savings on your shipping rate.

Still have DIM weight-related questions? The shipping experts at Worldwide Express can give you the answers, and also advise you on the best way to minimize the impact of costs on your shipping budget. Get in touch with us.