Traditionally, measuring a box is easy. You simply take a tape measure and run it along all the edges, taking notes as you do. When it comes to taking measurements for custom cardboard boxes, things are a little bit different… but don’t be intimidated by this! While the process may be different, once you know how to measure for a custom box you’ll be taking measurements like a pro.
The size of your cardboard box is dependent on a number of factors, and all of these need to be considered when placing your order. Not only do you need to know what is going to be put inside your custom cardboard box, but also the type and thickness of your packaging materials such as bubble wrap. Getting the right measurements also impacts your box, as if things are measured incorrectly it could result in a box that is too small or too large.
Read on for everything you need to know about measuring your custom boxes correctly and making the most of custom cardboard boxes!
The Big Question: How Exactly Do You Measure Custom Cardboard Boxes, using Inside or Outside Dimensions?
In short, it is most common to measure custom cardboard boxes using inside dimensions. At Jetbox, this is what we recommend to create boxes that perfectly fit your items and the relevant packaging materials. The reason why inside dimensions are the way to go for that perfect fit is because the internal dimensions are what the manufacturers use to create your boxes. Depending on the cardboard grade, the outside measurements can vary from between 1 to 10mm, allowing for excess unnecessary space.
While it may seem confusing to measure the internal dimensions, simply think of it as the usable space inside the box. This is the internal area you are measuring to ensure a perfect fit! While it may be impossible to measure an exact area taking into account bubble wrap or other packaging materials, get as close as you can while erring on the side of caution.
As an example, say your product is 10cm wide. If you place an order for your box using internal measurements of 10cm, the item will fit perfectly. However if you placed an order for 10cm using external measurements, the inside space would be less than 10cm as a result of the cardboard width meaning your product would not fit! Internal measurements ensure this doesn’t happen.
The Process of Taking Measurements for Your Custom Cardboard Box Using Internal Measurements

First, you measure the item or items you are shipping. Secondly, you estimate how much buffer your items will need to be safe. For example how many centimeters in bubble wrap, millimeters in butchers paper, or how large of a barrier using bio-fill you will need. As aforementioned, it’s better to overestimate by a little and add more packaging then being short on space.
That’s all you need to do! Remembering that the internal measurements are the inside measurements of the box, and not how big it will be when measured on the outside.
What If You Do Need To Use Outside Measurements For Your Custom Cardboard Box?

If you have specific needs for your box, such as shipping requirements, it may call for outside measurements. Some businesses rely on fitting into certain shipping price categories, and ordering boxes that fit into these categories is a must. If you do have these needs, and require boxes of a very specific external size, be sure to communicate with us and explain the measurements you are providing are external.
The 3 Measurements You Need To Supply
Your measurements need to be supplied in this order: length x width x height.
If you accidentally give your measurements in the incorrect order, you could receive a box that is totally different to what you expect. For example, a length of 100cm is very different to a height of 100cm! If you’re worried about this, feel free to email your provider with the measurements and adjoining sides eg length of 100cm.
As a reminder:
Length is the longest horizontal measurement of your box. It will be the longest opening dimension of your box.

Width is the shortest horizontal side. It is the shortest opening dimension of your box.

Height, or depth, is the vertical measurement. This measurement is the length between the top and bottom of your box when closed.

Australian Made Custom Cardboard Boxes with Jetbox
Ordering the correct size box is crucial when it comes to custom boxes. Not only does it play into the aesthetic, it also directly impacts the safety of your items in transit. Using our tips, you can place an order with confidence.
All our custom boxes are manufactured in our Melbourne warehouse by corrugated cardboard experts. Our years of experience have allowed us to learn everything there is about box manufacturing, and we offer durable and long-lasting boxing for affordable prices.
Still weary about the potential cost of ordering custom boxes? Use our custom cardboard box calculator for an instant quote today and be surprised by the affordability we offer!
Everyone here at Jetbox is passionate about creating the best experience for our customers! Feel free to send us your questions online. We can’t wait to be a part of your custom box journey.