How To Measure A Poly Mailer For Shipping?

WH Global Pack blog

Many businesses widely use poly mailers to ship products to their customers. These mailers provide a cost-effective alternative to heavy and bulky cardboard boxes. Poly mailers are flexible, so you can easily wrap them around the product. However, many people find it difficult to determine the right size of poly mailer for their product.

In this article, we will discuss why the right size of poly mailer matters, how you can measure the poly mailer for your shipping, and what size poly mailers are used for clothes. But before digging into that, let’s find out which industries use poly mailers for shipping. 

Which industries use poly mailers? 

Poly mailers are somewhat used for shipping almost every product especially delicate products like jewelry and electronics. Moreover, products like clothes, bedsheets, curtains, and shoes are also often shipped in poly mailers. 

E-commerce businesses always look for an economical and effective way to ship their products safely to their customers. Poly mailers are the best option for economical and effective shipping. Almost every business that is shipping use poly mailers for their order fulfillment. Small, medium, and large companies use poly mailers as their cost-effective way of shipping goods. However, it’s often difficult to determine which could be the right size for the poly mailer. In the next section, we will tell you why properly sized poly mailers are necessary and how one can determine the correct size of poly mailers according to the product. 

What size poly mailer do I need? 

If you need to buy poly mailers for your newly started e-commerce business, then you may face difficulty in finding the right size for different items. 

The right size for the poly mailer is not fixed. It varies depending on the item you are going to put in it. Poly mailers are usually used to ship softer items like stuffed toys, clothes, fabric, and bedding and small and delicate items like electronics, shoes, and jewelry. These mailers are lightweight, flexible, and tear-resistant. That’s why any product in a poly mailer is safe from damage. However, this can only happen if you select the right mailer size for every item.

An underfilled poly mailer increases the risk of mailers being snagged or caught during processing and sorting by carriers. Likewise, an overfilled poly mailer or one that is too small for the goods it will carry increases the likelihood of tearing and ripping the mailer. An over-filled poly mailer can also bust open during transit. 

If you want your product to arrive safely at your customer’s doorstep, you should choose the correct size of the poly mailer. 

How can I measure the right size of poly mailer for my product? 

To overcome the problems of underfilled or overfilled poly mailers, you need to do the following things:

Measure the exact size of your product 

Measuring the product’s size may seem obvious, but you have to write down the exact dimensions of your item to find the correct size of the poly mailer. Having all the product dimensions will tell you if you have found the right size poly mailer or if you have to go one size up or down. Carefully note the following dimensions:

  • Product’s length 
  • Product’s width
  • Product’s depth/product thickness 

If you use a larger size poly mailer, then you have to add an additional packaging material. Items like crumpled paper or packing peanuts are usually added to an underfilled poly mailer. On the other hand, it is generally difficult or nearly impossible to fit the item in a small-sized poly mailer. 

Account for packaging 

You have to take into account packaging while selecting the poly mailer. In the case of delicate items, you must add additional padding to ensure your item will reach the destination safely. So while making or purchasing poly mailers for fragile items, make sure that you have some extra space for your padding. 

Know shipping mailer dimensions 

If you are sourcing poly mailers from a supplier, check the dimensions of the mailer beforehand. Poly mailer suppliers can list the interior or exterior dimensions of their mailers. It would be better to match these measurements before choosing them for the desired item. 

Poly Mailer Size Calculator 

Once you know the exact measurements of your product, such as the product’s length, width, and thickness, it becomes easy to calculate the minimum height and width of the required poly mailer. To calculate the minimum width of the poly mailer, we have the following formula:

Minimum width = Width of item + thickness of item + 1”

The minimum width of the mailer should include the product’s width plus the product’s thickness plus add one. Using the above formula, you will get the minimum width of the poly mailer for your desired item. 

Likewise, to calculate the minimum length of your poly mailer, should use the following formula:

Minimum length = length of the product + Depth/ thickness of the product +2.”

The minimum length of the mailer should include the exact length of the product plus the depth or thickness of the product, plus add two inches. The length you will get after this calculation will be the minimum length of the mailer you should have. But if you want to add extra padding for delicate products, you should get one size larger bag. 

For example:

For example, if you have the product with the following measurements:

  • Product’s length: 8
  • Product’s width: 6
  • Product’s thickness: 2

Then the length × width of the desired poly mailer should be at least 12 × 9.

  • Minimum length = 8+2+2 = 12
  • Minimum width = 6+2+1 = 9

What size poly mailers are needed for clothing? 

Poly mailers are cost-effective, lightweight, and extremely handy compared to heavy cardboard boxes. Moreover, they come in a variety of unique colors and designs. Poly mailers are also easily customizable, that’s why they can give a professional and creative look to your shipping. 

However, if you are wondering what size is best suited to ship clothing, then know that they can be quickly shipped in a standardized poly mailer. But you can also measure your product according to the formula mentioned above and choose the poly mailer. 

In the case of clothing, first, determine whether you want to ship a single clothing piece or a stack of clothes. Your shipping poly mailer size will depend on the size, type, and pieces of clothes you are trying to pack. Even if you want to pack and ship a single cloth piece, you should not measure its dimensions without folding it. First, fold the cloth neatly and nicely. Take the dimensions of this folded piece and pick a poly mailer accordingly. If you take the unfolded fabric’s dimensions, your product will crumble in a large-sized poly mailer. 

General estimates

However, if you are not sure about the size of poly mailer needed for clothing, then here are some general estimates for you. You can check these if you don’t want to measure your dress and choose a poly mailer accordingly. 

  • 6 x 9”: can accommodate socks or tiny jewelry boxes. 
  • 7.5 x 10.5 inches: this can accommodate tea towels, socks, slightly larger jewelry boxes, and small electronics. 
  • 9 x 12 inches can stack up fabric patterns, a single T-shirt, or lightweight clothing like undergarments.
  • 10 x 13 inches can fit four to five big T-shirts, a set of napkins, a dress shirt, or one yard of fabric. 
  • 12 x 15.5 inches can fit three T-shirts, one dress, two pairs of jeans, or two dress shirts. A sweater or two to five yards of fabric can also fit in this size of the poly mailer. 
  • 13 x 16 inches poly mailers can fit a large jacket or sweater. 
  • To pack a stack of 12 to 14 medium T-shirts, two to three sweaters, 2 to 3 dresses, a set of jeans, three yards of fabric, or a bed sheet of a typically sized king bed, you have to use a 14.5 x 19 inches poly mailer.


Whether you are mailing jewelry items or clothing, the correct-sized poly mailer is a must. We have provided you with a simple formula to calculate what size poly mailer you should have. We have also provided what size poly mailers can be used for clothing. 

Maxwell Hua

Maxwell Hua | WHpack

Rapid Manufacturing Expert

I’m Maxwell Hua from WHpack, who has been focusing on the Courier Bags business for more than 10 years. I will always be committed to writing articles about the logistics industry, hope this will help you!

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