Product Guides

Package Shipping for Businesses: USPS Shipping Dimensions and Box Sizes

March 12, 2021
Inkit Team

When planning shipments, it’s essential to select a proper package size first, especially for business and e-commerce shipments, which are usually on a larger scale. Start planning the shipments from your store or delivering presents to your customers by determining the packages’ weights and dimensions: length, width, and height. Adhering them to the mailing services standards will ensure the timely delivery and predictable cost of the shipment.

If the package dimensions don't fit into standard USPS box sizes, you will pay more for mailing service, and it will take more business days to deliver the package. As nobody wants the ordered products to be expired, broken, or delivered past the holiday, the right package is essential. 

Get a step-by-step guide to selecting the right package for your business and e-commerce shipments in this article.

Measure Correctly: Package Sizes and Dimensions

The United States Postal Service (USPS) sets the package requirements and the price. One of the main factors of the price is the type of package and its size. 

Before we move onto the standard packages offered by USPS, let's determine the basic measurements to consider:

  • length - the longest side of the package, 
  • width - the second-longest side of the package, 
  • height - the smallest side of the package.

A tip for recording the measurements: round the value of all measurements to the nearest larger integral number of inches.

When it comes to measurements for mailing, there is an additional term here: girth. Girth is the distance around the thickest part of the package. To calculate the girth of your parcel, you should:

  • measure the width of the package and multiply it by 2,
  • measure the height of the package and also multiply it by 2,
  • then add those two numbers together. You will get the girth as a result. 

When measuring the irregularly-shaped products, imagine them packed into a rectangle box and measure their sides.

Dimensional weight, or dim weight, also matters. Sometimes it turns out to be much more than the actual weight of the parcel. So, study the USPS guidelines thoroughly to choose the right type of package. 

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USPS Priority Mail Flat Rate Products and Their Size Limitations

USPS Flat Rate Boxes.

Boxes come in three sizes: small, medium, and large.

The smallest box has a minimum length of 6 inches and a minimum height of 4 inches. If you need to send something smaller than these dimensions, choose the envelope packing.

The largest size of the package offered by USPS is 130 inches of combined length and girth. The maximum weight limit is 70 pounds. 

However, these measurements regard Parcel Select shipment. More common restrictions are 25 pounds for almost all machinable shipments and 35 pounds for shipments within the "Parcel Select" service.

If you need to send something larger, consider availing yourself of the services of UPS or FedEx.

USPS Flat Rate Envelopes

The flat rate envelopes are the best way to send paper documents with the dimensions of 8-½*11 inches, such as passport documentation. The rate is predetermined and doesn't depend on the weight at all.

Use USPS Retail Postal Price Calculator to calculate the exact price of the package. 

Why Use Address Verification Software when Planning Shipments?

Postage rates can differ, but sending to the wrong receiver will always cost you more, be it in the return cost, repeat send, or reputational losses.

To solve this issue, validate shipment addresses before scheduling the delivery. With Inkit Verify, your online store's customers will select their address in the correct format from a neat dropdown, eliminating the possibility of any human errors.

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