﻿ USPS Cubic Tier Resizing Calculator

Cubic Tier Resizing Calculator

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Calculates the cubic tier for a box, and the amount one dimension would need to shrink for the box to be in the next lowest tier.

Typically, boxes are easy to reduce in only one dimension - pick the option that makes sense if you're going to re-size a box, or look at all the options to get an idea of a different box you could use.

USPS Cubic Rate Priority is often the cheapest way to ship smaller / heavier items (up to 0.5 cubic feet and/or 20 lbs.) The cubic price is determined by distance (zone), and size (volume) corresponding to a "cubic tier" - Tier 1 to Tier 5 (smallest to largest.)

Sometimes the difference between a box being in a higher vs. lower tier is only a matter of a fraction of an inch or a few inches. If you can ship in a slightly smaller box that falls into the next lowest cubic tier (or re-size a box down), you may save a significant amount.

For example, shipping an item in a Regional Box A (RBA) costs between \$6.55 to \$10.31 (Zone 1 to Zone 8). The dimensions of an RBA would put it into cubic tier 3 (a more expensive rate than Regional A). However, an RBA re-sized just 0.1" shorter (or another box of a similar size) falls into cubic tier 2. Shipping a cubic tier 2 package costs just \$6.19 to \$7.95, so there's a potential savings of \$0.36 to \$2.36 over RBA.

Another more drastic example is a 10 lb. item shipping to zone 8 that fits in a 12 x 12 x 6.5" box (but is too tall for a Large Flat Rate Box). The best available rate would be regular Priority at \$34.57. However, if the item would fit in a box just 1/3" shorter (12 x 12 x 6.2"), it could ship cubic rate tier 5 for only \$17.02!

See this blog article for detailed explanations and examples.

Enter Outside Box Dimensions or Select a Box:

Box pre-sets:
X
Y
Z
{{cubicTier.error}}
Package is cubic Tier {{cubicTier}}.too large for cubic rate ({{ (cubicTier/10) }} cu. ft.) To reduce it to Tier {{targetTier}}, re-size the box one of the following ways:
To be eligible for cubic rates, the maximum size for any dimension is 18".
1. Reduce x by " ({{dims.x.reduced}} X {{dims.y.value}} X {{dims.z.value}}")
1. Reduce y by " ({{dims.x.value}} X {{dims.y.reduced}} X {{dims.z.value}}")
1. Reduce z by " ({{dims.x.value}} X {{dims.y.value}} X {{dims.z.reduced}}")
 1 Reduce x by " ({{dims.x.reduced}} X {{dims.y.value}} X {{dims.z.value}}") 2 Reduce y by " ({{dims.x.value}} X {{dims.y.reduced}} X {{dims.z.value}}") 3 Reduce z by " ({{dims.x.value}} X {{dims.y.value}} X {{dims.z.reduced}}")
This is already the lowest cubic tier.