Calculating Dimensional (Volumetric) Weight

Knowing how to calculate dimensional weight (also referred to DIM weight) is key to understanding an accurate cost of shipping product to customers. Regardless of if you decide to handle shipping logistics yourself, or if you outsource the process to a 3PL, it’s important to understand what dimensional weight is and how to calculate it. Read on to learn more about dimension weight calculation (and to find out how ShipCalm can help you)!

What is Dimensional Weight?

In the simplest terms, dimensional weight (DIM) is just a technique that’s used to calculate pricing for freight using the space a package will take up as a factor. It’s used by freight and shipping companies to make sure they don’t take a loss on lightweight but large products. While air freight has long used the dimensional weight concept to charge for shipping, it’s only been in the last decade or so that ground shipping has also begun to incorporate the technique to calculate cost. 

Looking at the volumetric weight (that is, how much space a shipment will take up versus only how much it weighs) can help freight companies make up for those large, lightweight shipments that may not result in much compensation from billable weight. 

So: dimensional weight calculation will determine if a shipping cost should be based on volume or size.

How to Calculate Volumetric Weight

Volumetric weight calculations are made by multiplying the width, height and length of a parcel to get the cubic size. Be sure to use the longest point of each side. Then, divide the cubic size by what’s known as the DIM divisor to determine the volumetric weight. Follow these step-by-step directions to get a volumetric weight calculation:

  1. Find the longest point of each side and measure width, height and length. If your package is not a perfect square or shape, add inches to account for any misshapen sides.
  2. Round each measurement to the nearest whole number.
  3. Multiply your dimensions (the rounded width, height, length) to get your cubic size. 
  4. Take the cubic size of your parcel and divide it by what freight companies call the DIM divisor (or dimensional factor). The DIM divisor is set by all of the major freight carriers like UPS, FedEX and DHL.

So for example, FedEx’s DIM divisor is 139 cubic inches per pound. So if your parcel is 26.6 x 16.2 x 10, you would multiple 27 x 17 x 10 = 4,590, divided by 139. This gives you a dimensional weight of 33.02. This number is then looked at compared to actual weight. 

  • If actual weight is less than 31 pounds, FedEx will charge for 31 pounds.
  • If actual weight is more than 31 pounds (as in this case), it will use that number for pricing.

UPS, Fedex & DHL Dimensional Weight Calculations

While different freight companies may calculate DIM weight a bit differently, they all use the same premise, and that’s to look at how much space a parcel takes up in relation to how much it actually weighs. Before deciding on which company to use, knowing the rules for each is helpful. 

UPS Dimensional Weight Rules

UPS uses billable weight to calculate rate. Billable weight is the greater of the dimensional weight versus the actual.

  1. DETERMINE ACTUAL WEIGHT: Round actual weight up to the nearest whole pound.
  2. DETERMINE DIM WEIGHT: Measure width, height and length in inches, round to the nearest whole number (up or down) and multiply. Divide by the divisor factor:
    1. Daily Rates = 139
    2. Retail Rates = 166
  3. DETERMINE BILLABLE WEIGHT: Compare actual weight to DIM weight. The greater of the two is the billable rate. This is the number that will be used to calculate the cost to ship.

FedEx Dimensional Weight Rules

FedEx also uses the greater of actual versus DIM weights. 

  1. DETERMINE ACTUAL WEIGHT: Round actual weight up to the nearest whole pound.
  2. DETERMINE DIM WEIGHT: Measure width, height and length in inches, round to the nearest whole number and multiply. Divide by the divisor factor:
    1. U.S., Puerto Rico and international shipments  = 139
      (note: this number was changed in January 2017; previously DIM weight was calculated using 166).
  3. DETERMINE BILLABLE WEIGHT: Use whichever is greater to determine your billable rate. 

DHL Dimensional Weight Rules

Like UPS and FedEx, DHL compares actual and DIM weight. 

  1. DETERMINE ACTUAL WEIGHT: Round actual weight up to the nearest half kilo.
  2. DETERMINE DIM WEIGHT: Measure width, height and length in centimeters and multiply by 5000 to get the DIM weight in kilograms. 
  3. DETERMINE BILLABLE WEIGHT: Use whichever is greater to determine your billable rate.

Dimensional Weight Pricing

If you’re concerned about the cost of shipping (what brand isn’t?), there are a few tips you can use to keep the billable weight cost down. 

  • Use the smallest box you can.
  • Some freight carriers may be willing to negotiate. 
    • Asking for a higher DIM factor can reduce your billable weight. 
    • Requesting a bigger cubic threshold could mean lower costs as well.
  • Inquire about incentives. Receiving added services and discounts might mean you can pass on perks to your customer, making your shipping cost lower and allowing you to be competitive by extending benefits your customers will appreciate. 

ShipCalm Can Help with Dimensional Weight!

Are you tired of trying to figure out how to calculate volumetric weight and rates on your own? Don’t want to mess with formulas and calculations, factors and dimensions? ShipCalm is an industry expert who can take the hassle out of shipping for you. What’s more? And we can usually offer better pricing and volume discounts. Reach out to ShipCalm today for a custom price. Save on shipping with ShipCalm.