Choosing the right mailer size can be tricky. Visually, it seems like an easy thing—if it’s bigger than your product, then logically it should work. But we know that’s not always the case. That mailer might be quite thick with padding inside, or your product may have an unexpected shape. Taking a step back to determine your product’s dimensions and confirm what mailer size it needs will save you from a lot of headaches.

We’re going to share with you a simple and effective formula that’ll ensure both product and mailer work together, avoiding time wasted and money needlessly spent.

Got your product and your measuring tape? Sweet. Let’s do this.

Step 1: Minimum Mailer Width

First up, let’s figure out the minimum width your mailer envelope needs to be. This measurement ensures the mailer can accommodate the width and height (thickness) of your product so it slides in easily, without leaving too much extra room for it to move around. The following formula accounts for the thickness of the lining in bubble mailers.

Formula: Product Width + Product Height + Add ¼ Inch = Minimum Mailer Width

  • Example: 3.5” + 1.5” +.25” = 5.25” Minimum Mailer Width

Step 2: Minimum Mailer Length

Now, let’s figure out the minimum length your mailer envelope needs to be. Much like minimum width, this measurement makes sure the mailer can fit the length and height (thickness) of your product. This way it’s easy to load, while at the same time ensuring any extra room that might let it shift around during delivery is limited. The following formula accounts for the typical thickness of the lining in padded mailers, and you’re also doubling the product height because of how much a flat mailer needs to expand to fit a three-dimensional object.

Formula: Product Length + Product Height + Product Height + Add ¼ Inch = Minimum Mailer Length

  • Example: 4.5” + 1.5” +1.5” +.25” = 7.75” Minimum Mailer Length

Step 3: Pick the Right Mailer Size

Now that you have both the minimum width and minimum length measurements, you can easily identify the right mailer size for the job. Any mailer that’s too small either won’t fit or your product or will be so tight it exposes your products to shipping damage. Mailers that are too big will be easy to load, but won’t keep your product in place, again exposing your products to shipping damage. The right mailer size is like the porridge in Goldilocks and the Three Bears—it’s just right.

You’ve likely noticed when looking through mailer sizes that they sometimes have groupings where the length is the same but the width changes, often by small increments. That’s the result of good market research—these are the mailer dimensions that accommodate the widest variety of product sizes.

Minimum Mailer Size: 5.25” x 7.75”

  • Example Options: 5×10”, 6.5×10”, 8.5×12”
  • Too Small: 5×9.25”
  • Too Big: 8.5×12”
  • The Right Mailer Size: 6.5×10”

What mailer’s right for your products? Read our shipping with mailers post for more info.

Choosing the right mailer size is important for your products. Taking a few moments to figure out measurements and do a little math can save you plenty of headaches down the road. You’ll avoid overspending on packaging supplies, reduce your shipping costs, conserve storage space and ensure your products are properly protected. We’ll see you over at our mailers category.