How to Measure a Shipping Box and Determine Package Dimensions

Most shipping companies charge by dimensional weight, which is calculated based on, you guessed it, the dimensions of a package. Determining package dimensions is no rocket science, but it is still worth knowing how to measure a shipping box the right way in order to get the best shipping rates.

The basic dimensions of a shipping box are length (L), width (W), and height (H). They are always written in this order: L x W x H. To determine the length of the box, measure the side of its longest flap. To determine the width of the box, turn it 90 degrees and measure the side of its shortest flap. Finally, to determine the height of the box, measure it from top to bottom with the flaps closed.

While the length of the box is the largest measurement for most packages, it is not always the case. If you’re using a tall box, its height may be larger than its length. That is why the length of a shipping box is defined as the length of its longest side with a flap and not simply as the length of its longest side. While length and width are measured horizontally, height is measured vertically and is the only dimension that does not include the flaps.

Keep in mind that a box can have inside (inner) dimensions and outside (outer) dimensions. When you purchase a shipping box from a distributor instead of getting it at a post office, the seller usually writes its inner dimensions in the description so that you know whether the items you’re going to ship will fit inside the box. However, to calculate the dimensional weight and shipping rate, you need to use the outer dimensions of the box, so you still have to measure it.

Many shipping companies also use the term “girth” when determining the maximum allowable dimensions of a package. The girth of a parcel is its circumference; it is calculated by taking the height and width of the package, multiplying each by two, and adding the results together. If you need to calculate the combined length and girth of your parcel, which is required by some shipping companies, simply add the length and girth measurements together.

You need to know the dimensions of your parcel to calculate its dimensional weight, also known as DIM weight or volumetric weight. We’ve already provided a detailed instruction on how to do it, so the only thing that we want to reiterate here is that it is calculated differently depending on whether the measurements are in imperial or metric units (i. e. inches or centimeters). If you measure in inches, you should round the measurements off to the nearest full inch before calculating the DIM weight.

How to measure a shipping box if you don’t have a ruler or measuring tape but need to determine parcel dimensions ASAP? There are tape measure apps that you can install on your smartphone or tablet and use them instead of a measuring tape. Keep in mind that they are based on the augmented reality technology, so your device should support AR.

iPhones and iPads running iOS 12 or higher typically have a built-in Measure App, so if you’re an Apple user, you won’t even have to download and install anything. If you have an Android phone or tablet, you can use one of the many measuring apps available on Google Play such as Moasure App, EasyMeasure, AirMeasure or AR Ruler App. Measuring apps usually have a tutorial that will make measuring easier for you.

If you don’t want to measure your parcel, you can take advantage of flat rate shipping that doesn’t require measuring and weighing the shipping box. All you need to do is pick a flat rate shipping box and make sure that the items you want to ship fit into it. Flat rate boxes already have specific shipping rates assigned to them, so there is no need to measure, weigh, or calculate anything.