Last updated: 5/15/2024
When it comes down to it, freight is all about numbers. What are the dimensions of your shipment? What’s the volume? The weight? How do I calculate cubic feet? How much will fuel cost? How can I determine my shipment’s freight class? Will my pallets fit in a 40-foot container?
Find the answers to these questions and you’ll know how to estimate your freight costs—and optimize your budgets.
We worked with our pricing team to put together some quick explanations of the most common freight math you’ll need.
We'll Show You How To:
- Calculate the volume of your shipment in cubic feet, the industry standard
- Find the density of your shipment (and understand the obscure “45-pound rule”)
- Use density to estimate the freight class of your shipment
- Calculate your fuel cost
- Figure out if your freight will fit into a standard-size container
With just a few simple formulas, you’ll be on the road to becoming a freight math expert in no time.
Cheat Sheet for Simpler Freight Math
Want an easy-to-use resource for calculating freight costs? Download a printable PDF for your office and workspace.
Calculating Cubic Feet (a.k.a. the Volume of Your Shipment)
In the world of freight, being able to calculate the cubic feet of your shipment is clutch. Cubic feet are a measure of volume—how much room your shipment takes up. This figure is especially important when it comes to:
- Ocean freight, in which shipments are often priced by volume in cubic feet. (Read more on ocean freight pricing.)
- Air freight, in which uses the volume of your shipment in cubic feet as well as its weight to determine your cost. (Read more about air freight pricing.)
Now that you understand why it’s important, let’s walk through how to calculate your shipment’s volume in cubic feet.
How to Calculate Cubic Feet Using Other Units of Measurement:
As we mentioned, cubic feet is a standard measurement used by the freight industry. But maybe you have your measurements in a unit other than inches. How would you get to a volume in cubic feet? Just use these handy formulas below.
How to Calculate Volume in Cubic Feet Using…
Feet
This one is just about as simple as it gets. It's almost exactly the same as the formula above for calculating using inches. However, we don't need a conversion factor since everything is already in feet:Length (in feet) × width (in feet) × height (in feet) = volume in cubic feet
So if your pallet measures 4′ in length, width, and height: 4 × 4 × 4 = 64 cubic feet
Yards
Calculating cubic feet using yards is pretty simple. However, we just need a quick conversion factor to turn yards into feet. Here's the formula:Length (in yards) × width (in yards) × height (in yards) × 27 = cubic feet
If our shipment measures 2 yards by 2 yards by 2 yards, our calculation would look like this: 2 × 2 × 2 × 27 = 216 cubic feet
Centimeters
Perhaps you prefer to use the metric system and measure your shipment in centimeters. We've got a formula for that, too:Length (in cm) × width (in cm) × height (in cm) ÷ 28316.846 = cubic feet
So, for example, if your shipment measures 2000 cm in length, width, and height, your calculation would look like this: 2000 × 2000 × 2000 ÷ 28316.846 = 282,517.3 cubic feet
Meters
Perhaps you prefer to use the metric system and measure your shipment in meters. We’ve done that math too!Length (in meters) × width (in meters) × height (in meters) × 35.315 = cubic feet
If your shipment is 5 meters in length, width and height, your math would look like this: 5 × 5 × 5 × 35.315 = 4,414.4 cubic feet
Keep these formulas handy, so when you’re requesting a quote or setting up a pick-up or delivery, you can supply your provider with the most accurate information possible.
Now that you understand freight volume, let’s cover freight density.
Finding the Density of Your Shipment (and Why It Matters!)
Once you’ve calculated the volume of your shipment in cubic feet, you’re already halfway to determining the density of your shipment.
But before we dive into the math, let’s talk about why density matters.
Density is one of the four factors that determines the freight class of your shipment.
And freight classification is one of the ways the industry simplifies and standardizes the shipping process.
- Freight class is one method carriers use to evaluate the “transportability” of a shipment. In addition to density, carriers also look at three additional factors to determine a shipment’s freight class: handling, liability, and stowability.
- Perhaps most importantly to you, freight class is also used to calculate shipping cost. Freight forwarders and LTL carriers both take freight class into account when putting together a quote, which is why it’s critical to understand your shipment’s density. (More on calculating your freight class from your density in a moment!)
The 45-Pound Density Rule
The “45 lb. rule” states that any shipments with a density greater than 45 lbs. per cubic foot will be rated according to this formula:
Total weight (in pounds) ÷ 45 = Chargeable volume in cubic feet
Let’s say you had a shipment that exceeds the cargo density limit (45 lbs. per cubic foot). Yours weighs 500 lbs., but it’s only 6 cubic feet. This is how your shipment would be rated:
500 ÷ 45 = 11 cubic feet
It’s a fairly simple formula, but it can become confusing when your invoice comes through. Good ocean freight forwarders and logistics partners should communicate this up front—and help you understand this pricing method. Don’t be afraid to ask us for assistance.
Now that you understand why density matters, let’s calculate it!
Calculating Freight Density: Start with the Weight of Your Load
Having a scale will help significantly. You can also look at your invoices from previous shipments for an assist. Just make sure you get your weight in pounds. Once you know your weight, grab the volume you calculated using the formula above, and run it through this simple formula:
Weight (in pounds) ÷ volume (in cubic feet) = density
So if you have a shipment that is 64 ft3 and 400 lbs., your equation will look like this:
400 ÷ 64 = 6.25 PCF
6.25 PCF (pounds per cubic feed) is the density of your shipment.
As you can see, this shipment is well below the 45-pound density limit we mentioned earlier.
How Do You Calculate Freight Class from Density?
Now that you have the volume of your shipment, how do you translate this number into a freight class?
First, keep in mind that freight class is determined by four elements: density, stowability, ease of handling, and liability. Even if you know the density of your shipment, the other three factors may change your item’s freight class.
However, now that you know the density of your shipment, you can use the chart below to estimate the freight class your shipment will likely fall into:
To get 100% certainty on your shipment’s freight class, talk to a freight forwarder or freight broker. If you get your freight class wrong, your shipment will have to be re-classed, which can come with extra charges.
Our team would be happy to help! Reach out for a free quote and we’ll help you figure out the right freight class for your shipment. Or, read more about this topic in our freight class explainer.
Now that we’ve covered volume and density, let’s talk about a couple of other freight math concepts you need to know.
Calculating Your Fuel Cost
Not knowing the price of fuel up front can lead to some unwelcome surprises when the time for payment rolls around. Be sure to ask your carrier which rate they will use when shipping your goods. With this information and the simple formula below, you’ll know exactly how much you’re expected to pay before you even see your invoice.
Total ocean charges × rate = Fuel cost
In other words, if the current rate of fuel is 24.5%, you will multiply your total freight charges by this percentage. For example, let’s say you are shipping your newest product less-than-container load over the ocean. Your shipment is a total of 450 cubic feet, and your total ocean charges (without fuel) are $1,575. Your calculation will look like this:
$1,575 × .245 = $385.88 in fuel charges
Want to know the total cost, including fuel charges? Here’s a little shortcut: add 1 to the fuel rate percentage before multiplying:
Total ocean charges × (fuel rate + 1) = Total cost
Easy, right? We recommend using a calculator (we always do!) so you know your calculations are accurate. You’ll be able to project and forecast your revenue and costs more precisely.
Will My Pallets Fit in a Container?
Finally, we’ve got one more crucial piece of freight math for you: Will my pallets fit inside the standard-size containers most commonly used by the freight industry?
Carriers try to maximize space by placing as much as possible in each container. This cuts down on costs for everyone involved. As a result, understanding these dimensions can be critical for optimizing the cost and efficiency of your shipments.
There are a variety of sizes available for shipping containers. Ocean freight forwarders and 3PLs deal mostly in 40-foot and 45-foot standard and high cube containers. To help you understand how many pallets you can fit in a container, take a look at the standard container measurements below:
| TYPE | 40-FOOT STANDARD | 40-FOOT HIGH CUBE | 45-FOOT CUBE |
| External Length | 40′ | 40′ | 45′ |
| External Width | 8′ | 8′ | 8′ |
| External Height | 8′ 6″ | 9′ 6″ | 9′ 6″ |
| Internal Length | 39′ 4″ | 39′ 4″ | 44′ 4″ |
| Internal Width | 7′ 8″ | 7′ 8″ | 7′ 8″ |
| Internal Height | 7′ 10″ | 8′ 10″ | 8′ 10″ |
| Door Opening Width | 7′ 8” | 7′ 8″ | 7′ 8″ |
| Door Opening Height | 7′ 5” | 8′ 5″ | 8′ 5″ |
| Internal Cubic Capacity (ft3) | 2,386 | 2,690 | 3,040 |
As you can see from the chart above, the differences in dimensions for the three most common shipping containers only vary slightly.
However, the extra inches and feet could mean the difference between having to spread your shipment out over multiple containers. In other words, if your goods hang over the edges of your pallets—making them wider than 4 ft.—you may not be able to place two pallets side by each. That means your shipment will take up more space and, ultimately, cost you more money.
The other thing you’ll want to consider is whether your freight is stackable. This goes back to the structural integrity of your product. If your goods can withstand the pressure of stacking, its footprint will be significantly reduced, allowing your freight forwarder to utilize the space alongside. This will often reduce the cost to you.
Great transportation providers will do everything they can to load safely, securely, while maintaining low costs for shippers. If you aren’t sure how your freight will “stack up,” you can always ask one of our experts for assistance. It’s like a giant puzzle, and we love finding solutions that work for everyone.
How Many Pallets Fit in a Container?
If your freight fits on a standard Grocery Manufacturers Association (GMA) 48″ x 40″ pallet, and your pallets can be stacked on top of each other, here’s what you can generally expect:
40-FOOT STANDARD
~20 pallets
40-FOOT
HIGH CUBE
~20 pallets
45-FOOT
HIGH CUBE
~20 pallets
* Remember that you’ve got an about an extra foot of internal space in a high cube container, so it may be able to accommodate (slightly) taller pallets.
Great transportation providers will do everything they can to load containers safely and securely, while keeping costs low for shippers.
If you aren’t sure how your freight will “stack up,” you can always ask one of our experts for assistance. It’s like a giant puzzle, and we love finding solutions that work for everyone.
All the Formulas to Make Your Freight Math Easy
Now that you understand the formulas behind all of this freight math, you’re on your way to becoming a freight–calculating machine!
If you want to get some practice, take some of the data you have from previous shipments and run them through the equations we shared above. If you’ve ever been mystified by the calculations on your freight invoices, this exercise may offer you some new insights.
Plus, the next time you need to quote out a shipment, you’ll understand both the “how” behind the calculations and the “why” behind the numbers, so you’ll be well equipped to optimize your freight budget for the future.
Cheat Sheet for Simpler Freight Math
Want an easy-to-use resource for calculating freight costs? Download a printable PDF for your office and workspace.
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