Understanding Package Forwarding: What is Dimensional Weight?


Here at the OPAS blog, we’re always keeping an eye out for new and interesting information we can pass along to members in order to maximize their access to US merchandise while minimizing their shipping bills.

Every now and then, though, we find it’s best to repeat information for the benefit of newer members, or those who aren’t members yet but are considering using OPAS to join the ranks of those who make use of a forwarder. Learning about dimensional weight (dims weight) is always a lesson that bears repeating.

So, a quick quiz: which do you think would cost more to ship, a big box of light, fluffy pillows at 26” x 20” x 12” that weighs 10 lbs…

…or a box of big, heavy books books at 12” x 12” x 8” that weighs 20 lbs.?

box of books[4]

Believe it or not, it’s the pillows.

In any international parcel shipment, the size of a shipment is just as, if not more important, than the weight. This is because there’s only so much room in the cargo hold of any international flight, which is the way that all international couriers OPAS uses transport your packages from the US to your country.

There’s a simple mathematical formula for determining a package’s dimensional weight: you multiply the 3 sides of the package together, and divide by 139 for any international shipment, or 166 for any domestic courier shipment.

H x L x W / 139 = dims.


So for our above examples, our pillows had a scale weight of 10 lbs., but a dimensional weight of 45 lbs.! (26 x 20 x 12 / 139 = 44.89, rounded up to 45 lbs.)

The books had scale weight of 20 lbs., but a dimensional weight of only 9 lbs. (12 x 12 x 8 / 139 = 8.29, rounded up to 9 lbs. – remember, all weights round up, dimensional or scale.) Unfortunately, this package will still be billed at 20 lbs. Because scale weight represents the minimum that can be assessed for any shipping weight.

So, as you can see, neither of these shipments is at its absolute peak efficiency. The pillows have 35 lbs. of dimensional overage (what we call it when dims weight exceeds scale weight) and the books are over on the scale weight side by 11 lbs.

At OPAS, we combat dimensional overage with a number of different techniques. If the box is bigger than the contents, we find a new box or cut down the existing one to fit as best as possible. If the contents are pliable, like pillows, we’ll compress them as much as possible and tape the box up very tightly so that it will maintain the smaller size. It’s our fastidious pursuit of dimensional-scale equality that makes it impossible for us to give a truly accurate shipping weight estimate until you’ve formally submitted a shipment request – considering we will hand-fit your items together like a jigsaw puzzle to reduce empty space and box size, we don’t take final measurements until the box is ready to go out the door.

How can you, as a customer, actively help us in reducing dimensional overage and pursue the best shipping cost? Think of it as balancing out items – obviously, heavy, dense items like books will have higher scale weight than dimensonal weight. Most electronics are the same. Clothing, shoes, handbags and other rigid, hollow items are the opposite, so you’ll want to combine these two different kinds of items together in shipments in order to reach balance.

Next time, we’ll discuss another option we use to overcome extreme, unpreventable dimensional overage: shipment by US Post.

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