Configuring Box Dimensions for ELEX WooCommerce Plugins

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The Problem

There is a lot of confusion around on how to properly configure box sizes for various shipping methods including USPS. In reality, this is not as difficult as it seems to be if there is a basic understanding of how packaging works. This article is an attempt to explain the basic concept with a few examples. Below example is explained taking USPS use case, but it is relevant even for our other shipping plugins too.

Configure ELEX Box Dimensions | Box Sizes

Box Sizes


What is outer and inner length? Simple. Taking an example of an order for a single product, Inner length is the dimension of the product and Outer Length is the dimension of the package.

By the way, the product dimensions can be updated at WordPress sidebar menu > Products > Edit individual product > Product Data meta-box.

Configure ELEX Box Dimensions | Product Dimensions

Product Dimensions

Notice by default weight measurement unit is set as “kg” and dimension as “cm”. This can be changed to “lbs” and “mm” at WooCommerce > Settings > Product.

Configure ELEX Box Dimensions | Product Measurements Units

Product Measurements Units

We are coming back to our topic. In the case of light weighted products like envelop, inner and outer dimensions will be the same. But, when there is some filling made to protect the product as like glass, electronic items, etc, the product (inner) dimension and package (outer) dimension will differ.

For example, suppose a product has an inner dimension of 20x2x1 and need to have a light filling while packing, the outer box size can be 22x4x3. Now, what if someone buys 10 number of it as part of a single order? Obviously, we need to consider shipping it as part of one single package. So, the outer box size should be 22x4x30. Notice only height changes as length and width remains same (think about the deck of cards).

Likewise, we need to define each logical box inner and outer sizes according to the packing style being followed for different products with different quantity.

Also, in case of heavy packing, Box Weight needs to be added in the corresponding field. This is the weight of the package and it will be added with the product weight to determine the shipping rates.  And if the total weight which is the sum of combined product and box weight, exceeds the entry in Max Weight, this box will not be the right one and so, another box will be chosen.


USPS Settings are located at WooCommerce > Settings > Shipping > USPS. Few key configuration elements are explained here.

Parcel Packing Method.

Configure ELEX Box Dimensions | Parcel Packing Method

Parcel Packing Method

By setting Parcel Packing Method drop down to default, each product item from the order will be considered as a separate package. Shipping cost will be calculated for every single quantity of the products in the cart.

Rest of the options are self-explanatory. Box dimensions must be defined as explained above to make it work.

Flat Rate Boxes.

Configure ELEX Box Dimensions | Flat Rate Boxes

Flat Rate Boxes

Flat rate boxes and envelopes are hardcoded in the USPS plugin code itself. There are a number of pre-defined box sizes and corresponding rates which will be picked up automatically according to your product dimensions and order quantities. This makes the job easier, but it may not be suitable for all businesses.

Use Case

I think a use case may help to get more clarity. Here is one.

Case 1: “Red Bag” single quantity. Product dimension 7x 11x .75 weight 20.
Case 2: “Red bag” quantity 20.

In the first case, the best fit found is this predefined box (d29).
“length” => “12.5”,
“width” => “9.5”,
“height” => “1”,
“weight” => “70”,
“online price” => “5.70”
In second case, it will getting packed to two predefined boxes (d22a, d17b).

Box 1:
“length” => “23.69”,
“width” => “11.75”,
“height” => “3”,
“weight” => “70”,
“online price” => “15.80”
Box 2:
“length” => “11”,
“width” => “8.5”,
“height” => “5.5”,
“weight” => “70”,
“online price” => “11.30”

So, 15.80 + 11.30 = 27.10


There are a number of services listed, where we can enable desired services. For more details on services provided by USPS, go through below link.

Tip of the Day.

While testing, if you face the issue of updated product dimensions and rates have no impact on the cart page, you can try disabling shipping rate caching.

You can go to WooCommerce > System Status > Tools, and enable Shipping Debug Mode by checking it on.

Configure ELEX Box Dimensions | WooCommerce System Status

WooCommerce System Status

Good luck!

Suggested reading: How to Pack Items based on Weight in WooCommerce?



Explore our blog section for more related articles.

You can also check out WooCommerce and WordPress plugins in ELEX.

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