Shipping Rate Calculator Guide

Shipping rates are calculated based on a variety of factors. The shipments’ dimensions, density, and weight, as well as where the product is going, how long it has to get there, and the requirements of the product in transit are all entered into a series of logarithms to determine final cost.

Carriers like USPS, FedEx, and UPS also calculate their shipping rates based on the ‘shipping zone’ the product is being shipped to. For an interactive map that details USPS shipping zones, click here.

Shipping product via Less Than Truckload (LTL) carriers requires classification into 18 different ‘freight classes’. These classes describe the products stowability (how easy it is to fit amongst other shippable products), liability (how likely is it something will go wrong in transit and how much such damages will cost), and ease of handling (can it be moved without special equipment). All freight carriers will require you to determine your own freight class, and may charge you significant fees if you input the incorrect one.

Nearly all carrier websites offer some form of calculator to do this math automatically. Below we describe the calculations being done on your behalf, so you can make the most informed decision possible on how you want to package and move your products safely and cost-effectively. 

Dimensional Weight (Also volumetric weight or DIM weight)

Carriers calculate their rates using either the actual weight of your product or the DIM weight. They select whichever is the highest to ensure the truck that it is placed on has the capacity to move it along with the other shipments onboard. 

The calculations require a different denominator based on whether the product is staying in the country or being shipped internationally.

  • Domestic Shipments: Length in Inches x Width in Inches x Height in Inches / 166 
  • International Shipments: Length in Inches x Width in Inches x Height in Inches / 139

Example: A box is 10 inches tall by 6 inches wide by 4 inches high.
Domestic Shipment: 240 / 166 = 1.44 DIM Weight
International Shipment: 240 / 139 = 1.72 DIM Weight
If the actual product weight was 1.2lbs, the carrier would use the DIM weight as it is higher.

Shipping Zones

US based carrier services use shipping zones in addition to the DIM weights. Shipping zones are calculated using Zip Codes and vary based on the distance between the origin and destination of a shipment. There are nine shipping zones and they are broken down as follows.

  • Zone 1: 1-50 miles
  • Zone 2: 51-150 miles
  • Zone 3: 151-300 miles
  • Zone 4: 301-600 miles
  • Zone 5: 601-1000 miles
  • Zone 6: 1001-1400 miles
  • Zone 7: 1401-1800 miles
  • Zone 8: 1801 miles or greater
  • Zone 9: US territories

Freight Class

All freight carriers require that a freight class be listed on the bill of lading. There are 18 freight classes that your product can fall under, calculated first by your pallet’s weight per cubic foot also known as its density, and then adjusted based on the other three factors (stowability, liability, and ease of handling). 

Freight class is calculated per pallet.

To calculate a product’s density, measure the height, width, and depth of each pallet in feet. Next, multiply the measurements (height X width X depth). If you already have pallet measurements in inches, then you’ll need to divide your measurements by 1728 (12inches X 12inches X 12inches) to get it into feet. The resulting value is the number of cubic feet the pallet will take up.

Now, you’ll divide the weight by cubic feet of the pallet in pounds (weight / cubic feet). This number is the density of your shipment. Compare the density of your pallet to the following table.

Density Greater than or Equal to Density Less than Freight Class
50 N/A 50
35 50 55
30 35 60
22.5 30 65
15 22.5 70
13.5 15 77.5
12 13.5 85
10.5 12 92.5
9 10.5 100
8 9 110
7 8 125
6 7 150
5 6 175
4 5 200
3 4 250
2 3 300
1 2 400
N/A 1 500

Example: A pallet is 4 feet by 4 feet by 5 feet and weighs 400lbs
4x4x5= 80 cubic feet
400 pounds / 80 cubic feet = 5 
The freight class is 175 as our resulting number is between 5 and 6.