Cubic Pricing

Bubble Briefs
Blog post May 29, 2019

What is Priority Mail Cubic Pricing and How to Access It

Confused about Cubic and SoftPack Pricing?

In general, Priority Mail Cubic Pricing can be one of the least expensive ways to ship small heavy packages.

More specifically, to qualify for any Cubic Pricing:

A package must be less than 20 pounds.

Have dimensions of not more than ½ cubic foot (L x W x H < 864).

Have no one side > 18 inches.

Cubic pricing is based on the dimensions of these packages, not on the weight. This can be a huge money saver for small packages 2-20 pounds.

Here is an Example:

10 pound package 12" x 12" x 5" going to zone 5
2019 Commercial Plus Priority Mail Rate	$19.51
2019 Cubic Pricing	$10.34
Savings	$9.17	WOW!

How to Access Cubic Pricing Rates

Originally, cubic pricing was only available to very large shippers. Lately, however, some shipping software services are making cubic pricing available to all online sellers. There are several providers who offer this service but Pirate Ship is the only service we know of that offers the service with no fees or markups to anybody who signs up for their free account. It is worth signing up for the service to access these great rates.
(While you are there, ask them about their amazing Simple Export Rates for small international packages.)

How to calculate Cubic Pricing Rates
(Note: If you are using Pirate Ship, the program will do this for you so you won’t have to worry about the math)

All cubic pricing is based on tiers.
For shipping in a box the tier is calculated by taking L x W x H / 1728 and rounding result up to next number.

Example: 12x8x4/1728=.22=tier 3)

Once you calculate your tier you can lookup up your shipping cost, by zone, in the following chart.
(These are the rates offered by Pirate Ship. Other service providers may have different pricing depending on how much of their discount they pass along to you.)

What is SoftPack Pricing?

SoftPack Pricing is a subset of the Cubic Pricing structure offered by the USPS for some Priority Mail packages. SoftPack refers to parcels shipped inside of bags/envelopes/sacks, even if boxes are contained inside the bags. Softpack tiers are assigned a bit differently, using only 2 dimensions.

The same pricing table as above is used to calculate shipping costs but the tiers are calculated differently.

How to calculate tiers for SoftPack:

Measure your empty envelope before you put anything in it. Do not count the lip that folds over to seal the bag.

Add together Length (rounded down to nearest quarter inch) + Width (rounded down to nearest quarter inch).

Use this total to find the appropriate tier according to the following chart:

Priority Mail Cubic Softpack Commercial Plus Pricing Tiers
Tier 1	Envelopes with a Length plus Width measuring more than	0" up to 21"
Tier 2	Envelopes with a Length plus Width measuring more than	21" up to 27"
Tier 3	Envelopes with a Length plus Width measuring more than	27" up to 31"
Tier 4	Envelopes with a Length plus Width measuring more than	31" up to 34"
Tier 5	Envelopes with a Length plus Width measuring more than	34" up to 36"

IMPORTANT: Note that the largest envelope that can be used for Softpack Cubic Pricing is 18” x 18” (not including the lip).

Any bag that has any dimension greater than 18” cannot be used for SoftPack pricing.

Examples:

A standard 9" x 12" unlined poly mailer is Tier 1 since 9 + 12 = 21

A standard 10" x 13" unlined poly mailer is Tier 2 since 10 + 13 = 23

A standard 12" x 15.5" unlined poly mailer is Tier 3 since 12 + 15.5 rounds up to 28

A standard 14.5" x 19" unlined poly mailer is does not qualify since one side is greater than 18"

Many "experts” are recommending using larger bags and folding them over. This is not a legal use of SoftPack rates. The dimensions that must be used are the dimensions of the flat bag before product is entered and no side can be longer than 18" before folding it over.

More specific rules can be found from the official USPS DMM rules.

Bubblefast has created two new custom size unlined poly bags for your convenience. They are 14" x 16" (Tier 3) and 18" x 18" (the largest legal size for Tier 5). Just look for sizes 14 and 18 in our unlined poly bag section.

If you ever ship heavy but small in size packages, definitely do some research and check this out. You’ll be glad you did.

If you have any questions about Cubic or Softpack Cubic Pricing Shipping feel free to ask.

Happy Shipping!
Mark & Robin Le Vine
Bubblefast
(877) 599-SHIP