What Cubic Pricing Tier Does My Package Fall Into?

In case you didn’t know, Priority Mail Cubic is a “secret” USPS mail class in which the postage price is based on the outer dimensions of your package, not weight. Shipping Priority Mail Cubic is the fastest and most affordable way to ship small packages up to 20 pounds with USPS. If you’re an E-commerce business owner, taking advantage of Priority Mail Cubic can be the difference between your business sinking or swimming! The good news is, you can do just that with free USPS shipping software. The next step is figuring out which cubic pricing tier your package falls into.

Calculating Your Cubic Pricing Tier

Depending on the size of your package, there are five different pricing tiers it will fall into. Cubic pricing tiers are determined by the total volume in cubic feet. We’ve listed those tiers in the chart below.

To determine which cubic pricing tier your package falls into, follow these steps:

1. Measure the length, width, and height of your package, rounding down to the nearest quarter inch. For example, if your package height is 5.2 inches, round it down to 5.25. If it’s 5.4, round it up to 5.5.
2. Once you’ve measured your dimensions, multiply them all together (Height x Width x Length). Then, take that resulting number and divide it by 1728.
3. Voila! The decimal you get is the size of your package in cubic feet. Refer to the chart above to determine the pricing tier, rounding up fractional results to the next tier (for example: if your package is 0.32 cubic feet, it will fall into the 0.4 tier).

Don’t Want to do the Math?

We don’t blame you. Feel free to use this Smart Cubic Calculator. Just type in your package dimensions, and it will automatically tell you which pricing tier your package falls into. The calculator even helps you optimize your dimensions, since package dimensions contribute directly to your bottom line!

What About for Padded Envelopes?

Calculating your cubic pricing tier for soft-pack envelopes is a little bit different (and easier). All you have to do is measure the length and width of the envelope, and add those two dimensions together! Remember: the sum cannot exceed more than 36 inches, and the total weight still can’t be more than 20 pounds. We’ve included a chart below, so you can see which pricing tier your envelope belongs to.