When it comes to shipping products, whether for e-commerce or business, the size and weight of your shipping containers can have a significant impact on postage costs. Shipping carriers like USPS, UPS, and FedEx charge based on various factors, with package dimensions being one of the primary considerations. Understanding how box and mailer sizes affect your shipping costs can help you optimize your packaging and save money.
The Relationship Between Package Size and Postage Costs
Shipping carriers typically calculate postage based on two main factors: weight and dimensional weight (also called volumetric weight). The dimensional weight is determined by the size of the package—specifically, the length, width, and height. It is especially important for lightweight but bulky items, as carriers use the greater of the actual weight or the dimensional weight to determine the shipping cost.
For example, a large, lightweight box might cost more to ship than a smaller, denser box due to its larger volume. The key takeaway is that bigger isn’t always better when it comes to shipping containers. Using the right size box or mailer for your products can lead to significant savings.
How Box and Mailer Size Affects Shipping Costs
Shipping carriers often use a pricing system based on dimensional weight pricing. This means that packages with a larger volume but lower weight are priced higher than expected, simply due to their size. Here’s a breakdown of how this works:
- Dimensional Weight Pricing: Carriers measure the space your package takes up, and if the package is large enough, the dimensional weight will be used to calculate the cost rather than the actual weight. This is especially relevant for light, bulky items like clothing or foam-filled packaging.
- Volumetric Weight Calculation: The formula to calculate dimensional weight for many carriers is:
(Length × Width × Height) / DIM divisor = Dimensional Weight
For example, USPS uses a DIM divisor of 166 for domestic packages. If a package is large but light, the shipping cost will be based on the dimensional weight, which could be much higher than the actual weight.
How to Reduce Postage Costs by Evaluating Shipping Container Size
To help you save on postage, here are a few strategies you can implement when evaluating your shipping containers:
1. Use the Smallest Box or Mailer That Fits
The first rule of thumb is to always use the smallest shipping box or mailer that comfortably fits your product. If your product can fit into a padded envelope or smaller box without being squished, choose that option to reduce excess space. Even a few extra inches in length or height can drastically increase your postage due to dimensional weight pricing.
2. Consider Poly Mailers for Soft Goods
If you’re shipping clothing, fabrics, or other soft goods, poly mailers can be an excellent alternative to boxes. These lightweight bags take up much less space and are typically much cheaper to ship, especially for items that don’t need extra protection. Be mindful, however, to ensure the product is adequately protected, as poly mailers provide less structure than boxes.
3. Optimize Box Shape and Dimensions
When selecting a box, try to match the shape of the product. Boxes that are overly large for the product inside waste valuable space and can lead to higher shipping fees. Consider custom boxes for irregularly shaped products—these boxes are designed to fit the item as closely as possible, reducing wasted space and the risk of being charged based on dimensional weight.
4. Check for Volume Discounts
If you’re shipping high volumes of items regularly, some carriers offer volume-based discounts for businesses. By negotiating with carriers like UPS, FedEx, or USPS, you may be able to secure better rates based on the average size and weight of your shipments. This is especially beneficial for businesses that consistently ship products in similar-sized packages.
5. Consolidate Shipments
If you’re sending multiple items to the same destination, consolidating shipments into one larger box rather than multiple smaller ones can help save on postage. However, be cautious—this can increase the overall size of the package, potentially raising the dimensional weight, so always check the total dimensions before combining shipments.
6. Use Flat Rate Shipping (When Applicable)
For certain carriers like USPS, flat rate boxes are available for a set price regardless of the weight (up to a specific weight limit). If you have heavier, dense items, using flat-rate boxes may be cheaper than calculating postage based on weight and dimensions. This option is particularly useful when you’re shipping products that are heavy but compact, such as books or metal parts.
7. Use Shipping Software to Calculate the Best Box Size
Many shipping software platforms, such as ShipStation or Pirate Ship, allow you to input package dimensions and weight to find the most cost-effective shipping option. Some platforms even suggest optimal box sizes to save on postage. Using these tools can help you avoid underestimating shipping costs and identify potential savings.
8. Reevaluate Packaging Materials
The materials you use for packaging can also impact your postage costs. For example, using heavier packaging materials such as thick corrugated boxes may increase the dimensional weight of a shipment. Instead, consider using lighter but protective materials like bubble wrap, air pillows, or tissue paper to reduce overall weight and volume.
Conclusion: Size Matters When it Comes to Shipping Costs
Shipping box and mailer size play a critical role in determining postage costs, especially with carriers that use dimensional weight pricing. By optimizing the size of your shipping containers to match your products, choosing the right mailer, and using packaging that minimizes wasted space, you can significantly reduce your shipping costs.
Remember, always evaluate your shipping containers before sealing the deal and weighing the costs. Small changes in box size and packaging material can have a big impact on your overall expenses, allowing you to keep shipping costs down and boost your profit margins. By following these simple steps, you’ll be able to reduce postage costs and streamline your shipping operations.