How to Measure Box Dimensions (Complete Guide)

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Getting the precise Measure Box Dimensions is the most important thing before you order boxes for your product. Why?

  • Because you obviously do not want to deliver your product in a clumsy-looking box, with your product ‘running around’ inside the box.
  • Neither do you want to pay extra bucks for the oversized boxes placed on the palette of the transport vehicle.
  • No one wants a box too extra-fitted to safely insert the product into it nor do they want to tear apart the box to be able to take the product out of it.
  • You definitely want your product to reach the customer in a single piece. Your product’s safety is at stake if the box does not provide a snug-fitting.
  • Above all, you do not want to waste your money by ordering the wrong sized boxes which do not fit your product, even if you miss the right size by half a centimeter.

Besides, it’s not just about the ill-fitting box with wrong measurements; it is even more about ruining your customer’s ‘box opening experience’ which DOES matter a lot in today’s competitive market. These boxes do not merely carry your product; they carry your company’s persona. Hence, the wrong size of a package can damage your image along with your product.

External Dimensions Vs. Internal Dimensions

External Dimensions Vs. Internal Dimensions

Measure box dimensions may seem as simple as using an inches tape to measure the length, width, and height of the box. But there’s a fix;

Are you measuring the internal dimensions or the external dimensions? Yes, that matters a lot. More than you might think. Actually, you do need to have a precise measurement of both the external and internal dimensions but for different reasons;

When it comes to getting a box with a snugly fitting product, you need to have an account of internal dimensions. These are important for perfectly fitting the items inside. But for this, first, you obviously need to measure your product’s dimensions. Ideally, your box’s internal dimensions should provide a room of around 1/16” on each side. I.e. once you have measured the dimensions of your product, add 1/16” to each of the three dimensions and you’ll get the perfect internal dimensions for your box. This would neither be too loose nor over-fitted.

However, keep in mind; these dimensions are excluding any extra space required for the cushioning material if you are going to use any. That will obviously require some additional space depending on what type of protective stuff you choose.

Now you must be wondering;

Why is it important to have an account of external dimensions when internal dimensions are all you need for ensuring a precisely fitting box? Why should you consider taking external dimensions into account? Here is why; Knowing your box’s external dimensions can actually help you estimate the transport cost.

It gives you an idea of how many boxes you can put on a palette of the vehicle per round and hence how many rounds you’d need for shipping your entire stock. Moreover, for fragile items, most companies prefer another outer, bigger box to carry one whole load of boxes. For that outer protective box too, you need to have the exterior measure box dimensions accurately. Measure the external dimensions once you get your boxes and use those measurements to estimate your courier cost if you are dealing in bulk quantities.

‘Know Your Box’-Identifying the Three Dimensions

No matter what shape your box will be, it is important to have an understanding of how many dimensions it has and what are they called. Only then you can provide accurate numbers to the packaging company for the required box size.

To start with, you need to know what the different dimensions of a box are. Although, you may already know that a box has three dimensions what’s important here is to know which one is called what. Because, you might be making very accurate measurements of each dimension, but it still can go terribly wrong if you don’t know which side is the length and which one is the height for example.

A box has three dimensions called length width and height. Before you get a measure box dimensions for them according to your product’s size, it is important to have knowledge of each one of these dimensions.

  1. Length;
    Length is usually the longest side of a box and there is a flap on this side. It is usually measured from the left to the right of your product and in most cases is the horizontal side except for the square boxes which have the same length and width.
  2. Width;
    Width is usually the second-longest side of a box. It too has a flap. Width is usually measured from the front to the back of your item to be packed.
  3. Height;
    Height is also referred to as the depth of a box. It is measured from the bottom to the top of the product and is mostly the shortest side of a box. Moreover, it is the only side that does not have a flap.

How to measure a box

However, it isn’t as simple as it might look;

Measuring the Dimensions of cylindrical Objects

Every product is not rectangular or square-shaped with length, width, and height clearly drawn out. What is your product is cylindrical for example? Here;

The length, width, and height would be identified differently. The diameter of the cylindrical product will be termed as its length as well as the width at the same time. Whereas, the measurement from the top to the bottom typically gives you the height or the depth of the product. So, the bottom line is;

Measuring the Dimensions of cylindrical Objects

In the case of cylindrical objects, you are technically dealing with two dimensions instead of three. Moreover, no matter what is the shape of your product, there is a box out there in the market for it. It all boils down to the box design you go for, depending upon your product’s shape and size. With proper measurements, you will certainly get the most perfectly fitting box for your items no matter how oddly shaped they are.

Things to Consider for Most Precisely Fitting Boxes

There are a few very important things that need to be kept in mind while measure box dimensions and ordering the right size from a packaging company. These may seem tiny, but if anyone of these points is neglected, it can play havoc and cost you a lot more than you expect. So, here is what you need to be careful about;

  • While sifting through the websites of different packaging firms are experts in ecommerce packaging and looking at the prices for different box sizes, bear in mind; the sizes mentioned are typically those for the internal dimensions. If these are mistaken for external dimensions, you may end up with a bit loose-fitting boxes and this, in most cases, means compromising on the safety of your product. This is important because most items need to be snugly fitted in the box to be completely secure.
  • Once you’ve measured (and re-measured) your product’s dimensions, never order the box with the same dimensions. Always remember to leave room for the fingers. After all, you do not want to drop the product from the top to get it inside the box. Moreover, you do not want a box that asks you to punch your product down forcefully. A little room is necessary for nice and snug product insertion.
  • If you are planning to insert some extra cushioning stuff into the box for protection, do not forget to leave some additional room for that depending upon the type of material you plan to use.
  • Try to be careful while selecting the thickness of the material you wish to use for your boxes. It can significantly change the external dimensions and hence can have an impact on how many boxes can be stacked up in the back of a vehicle to be transported in a go. It will affect the number of rounds needed for shipping your stock. Eventually, this will affect your shipping cost. The perfect thickness would be the one that combines protection, sturdiness, and cost-effectiveness at the same time.
  • Depending upon the box style you prefer, the measurements of length, width, and depth can vary significantly, so do not get deceived by what is what. For example, the taller boxes with the opening flaps on the top will have depth or height as the longest dimension and the length and width will be much smaller. Whereas, for the comparatively long boxes, the length will be the longest side with width and height significantly smaller. So, it might get a bit tricky and you need to pay attention to it.
  • When you look for the rates of boxes with different dimensions or place an order online for the custom boxes, you need to remember that the sizes are mentioned in the sequence of length × width × height. While placing your order, you also need to mention the dimensions in the same order because obviously, 600 × 400 ×300 is not the same as 400 × 300 ×600. So, the order matters a lot.
  • If you are dealing with a product that changes size after being treated, make sure, you wait for it to get in the final size in which it will be shipped before ordering a box. For example, soaps tend to shrink as part of the manufacturing process. Wait for them to get in the final size before taking measurements.
  • For those dealing in liquid or semi-liquid contents to be shipped inline boxes or boxes with a metalized bag inside, the volume of the box plays an important role. This can be obtained by multiplying length, width, and height.

Considering the Padding Requirements While Measure Box Dimensions

When the products have to undergo long transits before they reach their destination, or there is a chance that they might have to bear rough, careless handling, it just makes sense to add some extra padding into the boxes for increased protection. This is especially recommended for fragile objects. However, additional padding means additional space requirements.

So, the dimensions of your boxes will obviously change. You need to order a bigger size depending upon the type of padding you’d be using. For example, for bubble wrap, adding around 4 to 5mm space with each of the three dimensions would be fine. The bottom line is;

Cushioning Options for Packaging

Make sure, you leave room for cushioning before deciding the final dimensions of your product. Try to be as precise as possible while leaving a margin for the padding. You might consider one of these cushioning options;

Air cushions, bubble wrap, Styrofoam, tissue paper, crumbled newspaper, expandable foams, and many more.

Cushioning Packaging

For some, you may need more space than the other. So choose carefully as it will result in a significant change in the dimensions and the cost as a result. Make sure, you get a perfect combination of protection and value for money. It is a good idea to first test the cushioning with one box before you finalize the type of cushioning to be used. This can be done by dropping the packed item with the padding inside once or twice.

This will help you get an idea of how far your product can bear rough handling. Take into account any specific requirements by courier companies for padding. Most of them recommend around two inches of protective padding for breakable items.


To conclude, I would say, there isn’t a single item that cannot be shipped in a box that fits it perfectly and delivers in style. You just need to do some research and be careful while taking measurements.


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