How to Calculate the Size of Poly Mailer for Shipping

How to Calculate the Size of Poly Mailer for Shipping

Choosing the right size poly mailer is crucial when shipping products to customers. An undersized mailer can damage your items, while an oversized one leads to excess packaging material, higher shipping costs, and a larger environmental footprint. In this blog post, we'll guide you through calculating the perfect poly mailer size for your shipping needs.

I. Understanding Poly Mailer Dimensions

Before we dive into size calculations, let's clarify the three main dimensions of a poly mailer:

  • Length: The longest side of the mailer.
  • Width: The second-longest side, perpendicular to the length.
  • Depth/Thickness: The smallest dimension indicates how much space is inside the mailer.

II. Measuring Your Product

The first step in determining the ideal poly mailer size is accurately measuring your product. Use a ruler or measuring tape to record the following dimensions:

  • Length of the product
  • Width of the product
  • Height or depth of the product

If you plan to use additional packaging materials like bubble wrap or air cushions, measure their thickness as well. These extras will affect the required depth of your poly mailer.

III. Allowing for Wiggle Room

While measuring your product is essential, you must also account for some extra space inside the poly mailer. This wiggle room prevents your item from being tightly squeezed, reducing the risk of damage during shipping and handling.

A general rule of thumb is to add 1-2 inches to each dimension (length, width, and depth) to accommodate movement and cushioning materials. However, the amount of extra space required may vary based on the fragility and weight of your product.

IV. Considering Shipping Method and Handling

How your package will be handled during shipping can also impact the poly mailer size you choose. If you're using a courier service known for rough handling, you may opt for a slightly larger poly mailer to provide extra protection.

On the other hand, if you're shipping lightweight, non-fragile items via a gentler shipping method, you can get away with a snugger fit to reduce excess packaging material.

V. Exploring Eco-Friendly Options

As businesses become more environmentally conscious, the demand for sustainable packaging solutions is rising. If reducing your carbon footprint is a priority, consider using biodegradable mailers from plant-based materials like corn starch or sugarcane.

Not only are these polymailer bags better for the planet, but they can also enhance your brand's eco-friendly image in the eyes of conscious consumers.

VI. Choosing the Right Poly Mailer Size Based on Product Type

To help you visualize and select the appropriate poly mailer size, refer to this handy comparison table:

Comparison Table for Clarity:


Size Best For Examples
Small (6 x 9) Jewelry, trinkets, small books Earrings, pocket diaries
Medium (10 x 13) Magazines, documents, apparel T-shirts, glossy magazines
Large (12x15) Larger books, small apparel Hardcover books, sweaters
X-Large (18x18) Bulk clothing, larger items Sweatshirts, stuffed toys
XX-Large (19x24) Extra-large items, posters Blankets, large artwork


Poly mailers are a practical solution for a variety of products, particularly those that are long but not bulky. For smaller, more frequent shipments, the 6 x 9 poly mailers are a go-to choice, offering convenience and efficiency for any shipper.

Use this table as a quick reference guide when determining which poly mailer size best suits your particular products. Remember, it's always better to err on the side of a slightly larger size to ensure a safe and secure shipping experience.

VII. Branded and Designer Poly Mailers

Poly mailers can serve as a powerful marketing tool in addition to their practical purposes. Consider investing in designer poly mailers that feature your brand's logo, color scheme, and unique designs.

These branded mailers can create a memorable unboxing experience for your customers, reinforcing your brand identity and increasing the perceived value of your products.

VIII. Step-by-Step Guide to Calculating Poly Mailer Size

Now that we've covered the key considerations, let's break down the process of calculating the ideal poly mailer size step-by-step:

  1. Measure your product's length, width, and depth using a ruler or measuring tape.
  2. Add 1-2 inches for wiggle room and cushioning materials to each dimension.
  3. Consider the shipping method and handling conditions. Adjust the added wiggle room accordingly (more for rough handling, less for gentle shipping).
  4. Compare your calculated dimensions to the poly mailer sizes offered by various suppliers.
  5. Choose the smallest poly mailer size that comfortably accommodates your product with the added wiggle room.

IX. Tips and Best Practices

  • Avoid oversized poly mailers to minimize excess packaging material and reduce shipping costs.
  • Invest in designer poly mailers or custom-printed options to enhance your brand's image and create a memorable unboxing experience.
  • Explore biodegradable mailers made from plant-based materials to reduce your environmental impact.
  • Consider the weight of your product when selecting poly mailer materials. Heavier items may require sturdier mailers to prevent tearing or punctures.
  • Regularly review your poly mailer sizes as your product line evolves to ensure you use the most efficient packaging solutions.

By following these guidelines and calculating the appropriate poly mailer size for your shipping needs, you can ensure your products arrive safely, reduce excess packaging waste, and save on shipping costs. Happy shipping!

Need high-quality poly mailers for your shipping needs? Look no further than Our extensive selection includes standard, designer, and biodegradable poly mailers in various sizes to accommodate any product. With competitive pricing and fast shipping, is your one-stop shop for all your poly mailer and packaging requirements. Browse our collection today and experience the convenience of reliable shipping supplies.

Upgrade your shipping game with's poly mailers. We've got you covered, from small jewelry pouches to large apparel mailers. Order now and enjoy hassle-free delivery to your doorstep. Whether you're an e-commerce business, retailer, or individual seller, has the perfect poly mailer solution for you. Visit our website to explore our offerings and take advantage of our ongoing promotions.


More Posts


A general guideline is to add 1-2 inches to each dimension (length, width, and depth) of your product to accommodate
movement and cushioning materials. However, the exact amount may vary depending on the fragility and weight of your item. Delicate or heavy products may require more wiggle room, while sturdy, lightweight items can get by with less.

It's unlikely that a single poly mailer size will suit all your products, especially if you have a diverse product line. Refer to the comparison table in the blog post to match the appropriate poly mailer size with the type of item you're shipping. Using an improper size can lead to damaged goods, excess packaging waste, or higher shipping costs.

Traditional poly mailers are made from plastic, which can harm the environment. However, many suppliers now offer biodegradable mailers from plant-based materials like corn starch or sugarcane. These eco-friendly alternatives are a great way to reduce your carbon footprint while still enjoying the benefits of poly mailers.

Consider using cushioning materials like bubble wrap, air pouches, or packing peanuts to prevent excessive movement. Additionally, choose a poly mailer size that provides just enough wiggle room without being too spacious. To minimize shifting, you can seal the mailer securely with tape or adhesive strips.

Yes, poly mailers are suitable for international shipping if you choose the appropriate size and cushioning materials to protect your products during transit. However, check the customs regulations and restrictions for the destination country, as some may have specific packaging requirements or limitations.