E-Commerce Shipping with Stamps.com Online

E-Commerce Shipping with Stamps.com Online

Dimensional Weight Pricing applies to Parcel Select, Priority Mail, and Priority Mail Express packages across all USPS Postal Zones.


What exactly is Dimensional Weight?

  • Dimensional Weight refers to to how much space a package takes up in a truck or an airplane during shipping.
  • Dimensional Weight Pricing charges more for large packages that weigh very little.
  • Dimensional Weight Pricing only applies to packages larger than 1 Cubic Foot.
  • Most E-Commerce packages are less than 1 Cubic foot and are not subject to Dimensional Weight Pricing.
  • The USPS has been using Dimensional Weight Pricing in some mail classes and in some zones for some time.

Let me briefly explain Dimensional Weight Pricing. Let’s say there is a large USPS truck, the kind we see on the roads of our country every day, and that truck is filled with 200 large boxes, of pillows. Every one of those large boxes of pillows weighs very little, maybe 3 or 4 pounds. Now let’s imagine the same truck is instead filled with 200 boxes of shoes, small boxes, and each of those boxes also weighs 3 or 4 pounds. The boxes of shoes, being so much smaller, take up perhaps 20% of the space as the boxes of pillows, but being charged by weight alone, would cost the same amount for the USPS to transport. So, in the same size trailer, 5 times the number of boxes of shoes, 1000 boxes, could be shipped at the same time rather than the very large but very light 200 boxes of pillows, which would generate 5 times the revenue for the same truckload.

To balance the difference between size and weight, the USPS has adopteda formula for determining what the minimum shipping weight is for a box over 1 Cubic Foot in size, the Dimensional Weight, and uses that higher rate for larger boxes that weigh very little. The USPS has a formula for setting Dimensional Weight rates: A package dimensions are multiplied, Length X Width X Height. If the result is more than 1 Cubic Foot (1728 cubic inches), divide the result by 166 to determine the Dimensional Weight. If the postage rate for the Dimensional Weight is higher than the standard rate, that rate will apply to that package. Thankfully, our powerful software automatically compares the dimensions with weight to determine if Dimensional Weight Pricing is needed.

1 Cubic Foot may sound small, but is actually quite a large box. As a cube, a cubic foot is 12″ x 12″ x12″. ;Most E-Commerce boxes aren’t a cube, and any size box whose sides, when multiplied together equal 1 cubic foot, or 1728 cubic inches, or less, is fine. Here is a box you may be more familiar with, 18″ x 16″ x 6″. This is a common box size for goods sold online. When the length and width and height of this box are multiplied together,it is 1728 cubic inches, exactly 1 cubic foot. Any box smaller than these dimensions is less than I cubic foot and not subject to Dimensional Weight Pricing.

Dimensional Weight Pricing may sound intimidating but unless you ship large boxes that weigh very little you don’t have much cause for concern. Now, if you sell pillows in large boxes, you can expect to pay more for shipping.

How Will Dimensional Weight Pricing Affect My Business?

Dimensional Weight Pricing will increase costs for shipments larger than 1 Cubic Foot that weigh very little. Savvy shippers will find ways to minimize the effects of Dimensional Weight Pricing. Here are just a few suggestions:

1. Examine your products and the boxes you ship them in. Could they fit into a smaller box? The smaller a box you use will, as a general rule of thumb, reduce your shipping costs.

2. Our software is set to default to 1 cubic foot for Packages when no dimensions are entered. If you know your box is less than 1 cubic foot, select Packages. You don’t have to do anything different when shipping.*

3. If you know, or think, your box is larger than 1 cubic foot, select Large Package and enter the dimensions of your box. Our software will compare the size, weight, and distance to calculate the postage required.

4. Dimensional Weight Pricing will make calculating costs when offering free shipping a little more challenging. There is no such thing as free shipping. The cost of free shipping is paid for by the customer in the form of higher prices or absorbed by the seller as a cost of making the sale. It comes down to the margin of profit you, as the seller, feel comfortable with. If you are selling a million pair of shoes online, then a small margin can add up to a lot of profit. However, if you are selling hundreds of handmade sweaters, a reduced margin can spell trouble for your company. Examine your selling history and determine where your customer base is located. If you are in California and sell cold weather clothing to customers in Maine, your shipping costs could be too high to offer both free shipping and a competitive price. Yes, we know that free shipping is expected these days but it just might not be possible for you.

* If you ship a package large than 1 cubic foot without entering dimensions, any Dimensional Weight charges will be subtracted from your postal account as an adjustment.