Update June 29, 2026

Starting July 12, 2026, the U.S. Postal Service (USPS) will implement updates to the way dimensional (DIM) weight is calculated for certain services. These changes are intended to reflect the current cost of transport and align USPS pricing practices with current industry standards.

What Is Changing?

Dimensional weight pricing will apply to packages that exceed 1,728 cubic inches (one cubic foot):

• The divisor used to calculate dimensional weight will change from 166 to 139.
  • This means that larger, lightweight packages may be assigned a higher dimensional weight than they are today, resulting in higher postage costs for some shipments.
• USPS will also adopt a standardized rounding method for package dimensions in dimensional weight calculations.
  • Any fraction of an inch will be rounded up to the next whole inch. For example, a package measuring 12.2 inches will be calculated as 13 inches in calculation.

Services Impacted

The following services will be affected:

• Chit Chats U.S. Select
• Chit Chats U.S. Edge
• USPS Priority Mail
• Chit Chats U.S. Connect 

What This Means for Your Shipping Costs

As a result of these changes, some shipments may see changes in postage costs beginning July 12, particularly larger parcels that are lightweight relative to their size. Because dimensional weight will be calculated differently, postage costs for affected shipments may change even if the package’s actual weight remains the same.

We encourage you to review package dimensions carefully and find ways to reduce the volume of your shipments if possible. To understand how dimensional weight works refer to our resource here. The article will be updated with the new methods as of July 12.

We’re Here to Help

We understand that changes to shipping rates can affect how you run your business. That’s why our team is here to help.

Book a call with one of our specialists for personalized support and practical tips on how to adapt to these changes. We’ll work with you to understand the potential impact on your shipments and help you find the best path forward.

Learn more about dimensional weight below.

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Postage rates are calculated by the weight of the package and the dimensions. When postage is calculated based on dimensions this refers to dimensional weight. This is a common industry practice with shipping carriers like USPS, FedEx, Canada Post and UPS to name a few. Carriers will calculate postage based on the greater of the two: actual weight or dimensional weight.

What is dimensional weight?

Dimensional weight, also known as volumetric weight, is a standard for which carriers use to calculate postage. It is calculated from the length, width and height of a package. For example if you have a 5 lb package that is packaged in a larger box (i.e. 20″ x 20″ x 20″), this package will take up more space (volume) than if it was in a box with smaller dimensions (i.e. 5″ x 5″ x 5″). Therefore carriers will charge postage based on the dimensional weight versus the actual weight.

It is always important to be accurate with your weight and dimensions to ensure you pay accurate shipping costs.

• Avoid underestimating dimensions or weight. Most carriers will always round up weight to the next point. For example, USPS will calculate postage for 1.3 lbs at 2 lbs.
• Postage adjustments may be applied for inaccurate weight and dimensions.
• Shipments can be returned to sender or delivered to your customer with postage due if postage is inaccurately purchased for your package.

Your packaging matters! Package your item as small as possible to minimize extra packaging that could be factored when calculating shipping costs.