The Basics of Dimensional Weight and Its Impact on Shipping Costs

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Have you ever had the problem that you want to ship something slightly larger but are afraid to use the larger box because you thought it might cost more compared to standard packaging?

Well, that’s one of the main concerns for every seller when it comes to shipping their products to their customers. 

If you’re an E-commerce business owner, you would have already figured out that shipping expenses represent a considerable portion of a business. And that is a massive problem regarding expenses for your business.

What if I told you that there’s a solution to this problem? 

The secret is simple. You’ll have to know the weight of your parcel.

No, not the physical weight, but the ‘Dimensional Weight’.

What Is Dimensional Weight?

Dimensional weight is the weight of a parcel measured by taking the size or measurements of the parcel into account. In other words, it calculates the amount of space that a parcel will take when it is transported and compares it to the actual weight of the parcel.

Dimensional weight is also widely shortened as a DIM weight and is used by all courier companies to calculate the cost of parcels or packages. 

Wondering what's the unit used to measure dimensional weight? That depends on the country you're in. Here in Malaysia, we use KG to measure a parcel's dimensional weight. (Yes, it's the same unit used to measure the physical weight!)

With dimensional weight, courier companies can determine how to charge the parcels you are trying to ship. This is so cases such as a box of bricks and a box of ping pong balls being charged the same amount will not happen.

How Is Dimensional Weight Different From Physical Weight?

As you may have already guessed, dimensional (or volumetric) weight is the cubic or volume of the parcel while physical weight is the actual weight of the parcel. 

Taking into account both the dimensional weight and the physical weight of a parcel is crucial when calculating the shipping fee for a parcel.


With both measurements, a courier company will be able to compare both types of weight to calculate the correct shipping fee for a parcel.

Dimensional Weight vs Physical Weight

If you’re wondering which weight will be taken into account when couriers charge shipping costs. There’s something called the ‘Carrier’s choice’ or ‘Which ever is greater’. This simply means that whichever weight has a greater value will be the amount that will be taken into account whenever calculating a shipping price. 

In other words,  if the parcel’s physical weight is heavier than the dimensional weight, a courier company will use the parcel’s physical weight instead of the dimensional weight to calculate the shipping cost and vice versa. 

How To Calculate Dimensional Weight

What’s that? Maths is not one of your strengths?

Don’t worry, calculating a dimensional weight is just a matter of multiplying and dividing.

So worry not, let’s take a look at the formula to calculate a parcel’s dimensional weight!

(Parcel’s Length X Width X Height) / DIM Factor = Dimensional Weight (cm³/kg OR in³/lb)

Dimensional weight is calculated by multiplying the parcel’s length, width and height and dividing by the DIM factor that is determined by the shipping company.

The result will then be used to compare to the actual weight of the package. And as we’ve said just now, the higher of the two values will be used to calculate the shipping cost. Yes, it’s as simple as that.

What Is a DIM Factor?

A question you might have right now is what is a DIM Factor. 

A Dimensional factor (DIM Factor), sometimes known as the DIM divisor is a set of numbers used to determine the DIM weight of a parcel. It represents the volume of a package allowed per unit of weight.

This set of numbers is determined by the courier company and each DIM factor is different depending on the type of shipping method and the courier company. DIM factor comes might differ depending if you're using the cubic inches per pound or cubic centimeters per kilogram.

Below is a more commonly seen DIM factor if your parcel is weighted in KG:

  1. Sea Freight: (1:1000)
  2. Air Freight: (1:5000)
  3. Rail Freight (1:3000)
  4. Road Freight: (1:3000) 

*Do take note that these DIM factors are just for reference  and will vary based on company and if your parcel is weighted with pounds. 

Freight Rates

Wondering what you'll need to do next once you’ve gotten the dimensional weight of your parcel? You'll next need to multiply it with the freight rate.

Freight rates are the price that a company imposes on helping clients or customers deliver their items. Each courier will have different freight rates that they impose on their customers. 

So remember to check the freight rates for each mode of delivery with the courier company you desire to better clarify your shipping costs. 

Example of Calculating Shipping Cost:

In this section let’s just create a scenario where you’d want to send out your parcel to your customers.

Say that you’d like to send a parcel using the courier’s air delivery. Take out your measuring tape and let’s measure the parcels together. 

I’ll go first, here are the measurements of our parcel, the courier’s DIM Factor and Freight rates.

  1. Dimensions (CCM): 120CM X 75CM x 60CM
  2. The air freight DIM factor is 1:5000
  3. Freight Rates: RM5/KG

As we’ve said just now, you will just need to incorporate the numbers that you’ve measured into the equation that we’ve provided just now. In our case, this makes it:

(120 X 75 X 60)/5000 = 108cm³/kg

Once we’ve found out the dimensional weight of the parcel, you will just need to use the amount and multiply it by the freight rate. 

90 X RM5 = RM 450

And there you have it! Who would’ve thought that calculating the shipping fee for your parcels is that easy?

However, as we mentioned, if your physical weight is higher than the DIM weight, the courier will use the weight that has the greater value to calculate the shipping cost. 

What Can You Do With This Information?

With the correct information, you can now calculate your parcel and choose the correct type of shipping box for your parcel. You can take advantage of this information and optimize the way you pack your parcel!

Want to try out our very own Dimensional Weight Calculator? Give it a try here! 

How To Ship Optimally?

Yes, as you may have already noticed, it’s hard to ship ‘cheaply’. However, as frequent users of courier services, what we can do is ship ‘optimally’. Below are a few tips that we can give when it comes to shipping in an optimal way. 

  1. Fit your item into a smaller box.

  2. Change the materials you use to wrap your package 

  3. Remove the product from its factory-made packaging if you think it takes up too much space.

  4. If all doesn’t work you can choose to ship your parcel in two packages if the cost seems fairer by splitting it into two parcels. 

We hope that you’ve learned a thing or two about dimensional weight and how dimensional weight is one of 2 keys to understanding how a courier calculates a shipping cost.