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Dimensional weight: you pay for the air.
Carriers do not bill the weight on the scale. They bill whichever is higher, the actual weight or a weight calculated from the box's volume. For anything light and bulky, that second number is usually much bigger, and the divisor behind it is negotiable.
How it works
Length × width × height, divided by the divisor
The formula is simple. The consequences are not.
Multiply the three dimensions of the box to get cubic inches, then divide by the dimensional divisor in your carrier agreement. 139 is the standard retail figure. The result is the dimensional weight, rounded up to the next whole pound. You are billed on that figure or the scale weight, whichever is greater.
A worked example
Take a box measuring 21 × 14 × 9 in that weighs 8 lbs.
21 × 14 × 9 = 2,646 cubic inches.
2,646 ÷ 139 = 19.03, which the carrier rounds up to
20 lbs.
The box weighs 8 lbs. You are billed for 20. You pay for an extra 12 lbs on every single one of those shipments, purely because the divisor is low.
Now run the same box at a divisor of 194: 2,646 ÷ 194 = 13.64, rounded to 14 lbs. The same box, the same contents, six pounds cheaper. Nothing about your operation changed.
Why a higher divisor is worth having
A higher divisor produces a lower dimensional weight, which means less billable weight on every oversize or low-density package you ship. It compounds in a way a percentage discount does not: the divisor reduces the weight that every other charge is then calculated against, including the base rate.
For a catalogue of light, bulky product — home goods, outdoor gear, anything shipped in a large carton — negotiating the divisor up from 139 is frequently worth more than a larger percentage discount on the base rate. It is also the term shippers are least likely to ask about, which is exactly why it is often available.
Calculator
Test your own box against every divisor
Enter the dimensions and weight of a box you ship regularly. The calculator shows the billable weight at your current divisor, how many pounds of air you are paying for, and what every other divisor would produce.
Your box
Length × Width × Height
Billable weight
Every divisor, same box
| Divisor | Dimensional weight | You are billed |
|---|
Dimensional weight is rounded up to the next whole pound. The billed figure is the greater of dimensional weight and actual weight.
Related
Dimensional weight is one of several charges that stack on a large box.
Find out what divisor you are actually on.
Send us your rate agreement and a recent invoice. We will confirm your divisor, model what a better one is worth across your volume, and tell you whether it is winnable.