How to Measure a Box

Boxes come in all shapes and sizes. They can be square, rectangular, triangular, round, or even shaped like flowers or purses. Most boxes have four sides and those with fancy shapes may have even a few more sides. One thing they have in common is that boxes are three-dimensional, meaning we can pick them up, rotate them, and put stuff inside.

A three-dimensional object includes three measurements, such as height, width, and depth. Sometimes people will call out these measurements differently, but the reality is that all boxes are measured in the same way.

How are boxes are measured?

The system of measurement, whether it be inches or centimeters, doesn’t magically change from box to box. On paper, however, measurements are sometimes listed in different ways, depending on the industry. With shipping and packing boxes, the industry calls out the measurement of boxes as Length x Width x Height (L x W x H). In our catalog and website, we list box dimensions as Width x Depth x Length (W x D x L).

Both have three measurements, and while they don’t appear to be the same thing, here’s the catch. They are actually the same, but they are simply named differently. How do we sort this out?

In a nutshell, boxes are always measured in the same way with the first two measurements signifying the opening side.

To make things simple, you might think of dimensions represented in the following way:

Longer opening side   x   Shorter opening side   x   How far down the box goes

The most important thing to know is that the first two measurements indicate the opening side. The longer of these two measurements will be the one that is listed first.

Open side is determined by the first two measurements

How far down the box goes is what you see when you are looking down into the opening of the box. This is the remaining measurement, referred to as either height or length.

See the infographic below as a guide:

How to Measure a Box Infographic

Why are dimensions listed in different ways?

Packing boxes are commonly measured as L x W x H. As noted above, we list our dimensions as W x D x L for our products. So, why the difference?

In a packing box, customers normally recognize the top of the box first. Think about those holiday boxes that come in the mail. The flaps fold in and the longer flaps meet together to close the box. Well, these closed flaps are also the opening of the box.

However, we list dimensions for our products differently because of our unique perspective of photo and stationery packaging. In a clear box, customers look at products from the largest viewing panel available, usually with their eyes looking straight into the middle of the box and not from the top. This preferred presentation has prompted a slightly different naming of dimensions. In this type of packaging, customers consider the depth in terms of how tall a box needs to be to hold a stack of photos or cards.

So, you could say, we name things to align with how our customers think about their products.

Let’s look at a few examples to solidify this idea.

Example 1: Tall and Lean vs. Short and Wide

We’re going to take a look at two boxes, the VB300 and the FPLB179. They have similar dimensions and one main difference, where they open.

The VB300 measures 3″ x 3″ x 7″ (W x D x L). Let’s start with the first two measurements, the 3 x 3. This is where the opening side is as you can see in the image below. These two measurements are the same but were there to be a longer side, it would be listed first. On a single-piece box with a directional opening, the first measurement also signifies where the opening is. Looking down into the box, the last measurement is 7 inches, making it tall and lean.

crystal clear box

Now let’s look at a box with a short and wide orientation with similar measurements. Our FPLB179 measures 7″ x 4″ x 3″. Although not the exact measurements of our VB300 box, they are similar. Again, start with the first two measurements to pinpoint the opening, the 7 x 4. The longer side or opening side is listed first,; then looking down into the box we measure 3 inches,  making this box short and wide. Here is what it looks like:

crystal clear box

Since the above examples are similar in size, you could conceivably use the same box to display a product. The big difference between these boxes is where they open and what is considered the “top” of the box. As this is how your customers will be introduced to your product, this is a key difference and one you want to get right!

Example 2: Photo Boxes

Let’s look at an example of how boxes are measured using our photo boxes. These boxes can hold anywhere from a few photos to up to hundreds of photos. You’ll see that in the following two boxes, the dimensions vary based on where the box opens. Both of these boxes hold 5 x 7 photos and have the following measurements:

FPB162: 5 1/8″ x 5/8″ x 7 1/8″ (Holds up to 50 photos)

FPLB213: 7 1/8″ x 5 1/8″ x 3″ (Holds up to 300 photos)

Notice that the FPB162 photo box opens on the 5 1/8-inch side (the longer of the first two opening measurements). The 5/8-inch measurement is the second of the opening measurements, and from a photo perspective, indicates the depth of the box.

crystal clear box

An interesting thing happens when we have a box with similar dimensions that has the longest side listed first. The FPLB213 box opens with the 7 1/8-side and lists the second dimension as 5 1/8″. Then, looking down through the opening (the third measurement) you get the final 3 inch measurement.

crystal clear box

So, you can see that while these boxes are intended to hold the same product, the way the measurements are listed drastically changes how the box functions.

Unique Box Shapes, Unique Measurements

As we know, not all boxes are four-sided. Boxes with unique shapes are a bit more complicated to measure. For example, take the pillow box. The pillow box offers a fun, eye-catching alternative to the traditional rectangular or square box. Here, curved, half-moon flaps are folded in on the sides to form the unique pillow shape that this box is named after.

A pillow box is measured as W x D x L, as follows:

  • Width is the flattened measurement of opening side
  • Depth is how thick the box will be once assembled, measured from the center and tallest point of the curved flap; when the box is assembled, it is the highest point of the moon shape
  • Length is measured top to bottom from outside corner to outside corner
  • Middle Length, often listed separately, is the usable space of the box, measured from the shortest point between the two flap sides

When assembled, the curved flaps of a pillow box are pushed inward, which reduces the usable space available. As an example, let’s look at the PB100 box.

pillow box

The PB100 measures 2 1/2″ x 7/8″ x 4 (W x D x L). To estimate the amount of length available, we use the middle length, measuring from the lowest point of the curved flap extending to the lowest point of the other side. In this box, this measures 3 1/8″. So, this is a reduction of 7/8″ space from the 4-inch length dimension given to this box.

Final Thoughts

The importance of measuring a box correctly can’t be underestimated. Luckily, measuring a box is really pretty easy — Boxes always open according to the first two measurements listed and the longer side will be mentioned first. The final measurement is how far down the box goes when looking through the opening.

We hope this post has helped better understand how boxes are measured. If you ever find yourself confused, don’t worry. Work through the dimensions and, remember, the most important thing is where the box opens!