Container Loading Calculator

Q: What container sizes does this calculator support?

The calculator includes 20-foot, 30-foot, 40-foot, and 45-foot containers in both standard and high-cube heights. It also has 20-foot and 40-foot refrigerated (reefer) containers. If your container is not on the list, pick Custom Container and type in your own inside dimensions, payload, and tare weight.

Q: What is the difference between Simple and Complex stacking modes?

Simple mode picks the single best orientation for each product and packs it that way. It runs fast. Complex mode tries multiple orientations for each item and places the heaviest items first. It usually fits more cargo but takes a bit longer to run. Use Complex mode when you have mixed cargo sizes and want the tightest possible pack.

Q: Can I load different product types into the same container?

Yes. Click Add Product to create as many different cargo types as you need. Each product gets its own size, weight, quantity, color, and packing rules. The calculator packs all of them together into the same container or containers.

Q: How does the Best Container Recommendation work?

When you click Best Container Recommendation , the tool adds up the total volume and weight of all your cargo. It then checks every built-in container size and picks the smallest one that fits everything at about 85% packing efficiency. If no single container is big enough, it suggests the largest container and tells you how many you need.

Q: What does space utilization mean?

Space utilization is the percentage of the container's inside volume that your cargo fills. For example, 75% means your cargo takes up three-quarters of the available space. A higher number means less wasted space and a more efficient shipment.

Q: What does weight utilization mean?

Weight utilization is the percentage of the container's maximum payload that your cargo weight uses. If a container holds up to 28,000 kg and your cargo weighs 21,000 kg, weight utilization is 75%. You must stay at or below 100% to avoid overloading.

Q: How do I stop items from being stacked on top of each other?

Check the No Stacking box on that product card. The calculator will not place any other item on top of it. You can also check Fragile , which does the same thing and adds a visual tag to remind you the item is breakable.

Container Loading Calculator

Updated Jul 12, 2026 By Jehan Wadia

Introduction

This container loading calculator helps you figure out how many items fit inside a shipping container. Enter the size and weight of your cargo, pick a container type, and the tool does the math for you. It shows how much space and weight you use, how many items fit, and which ones do not. You also get a 3D view of how your cargo sits inside the container so you can see the layout before you ship.

The calculator supports all common container sizes, including 20-foot, 40-foot, and 45-foot options in both standard and high-cube heights. You can also add a custom container with your own dimensions. It works with boxes, big bags, and sacks, and lets you set rules like no stacking or fragile handling. Whether you are loading one container or many, this tool gives you a clear plan to maximize space, stay within weight limits, and avoid costly mistakes.

How to Use Our Container Loading Calculator

Enter details about your cargo and shipping container below. The calculator will show you how many items fit, how much space and weight you use, and give you 3D and 2D views of how your cargo is packed inside the container.

Length Unit: Pick the unit of measurement for all sizes. Choose from millimeters, centimeters, meters, inches, or feet.

Weight Unit: Pick the unit for all weights. Choose kilograms or pounds. If you need to convert between the two, use our Kg to Lbs Calculator.

Calculation Name: Give your calculation a name so you can find it later. This is optional.

Number of Containers: Enter how many containers you plan to use for this shipment.

Product Name: Type a short name for each cargo item, such as "Carton A" or "Pallet B."

Color: Pick a color for each product. This color is used in the 3D view and charts so you can tell items apart.

Cargo Type: Select the shape of your cargo. Choose Box, Big Bag, or Sack.

Quantity: Enter the total number of pieces for that product you want to load.

Length, Width, and Height: Enter the outer size of one piece of your cargo in the unit you chose above.

Weight per Item: Enter how much one single piece weighs in the unit you chose above.

Allowed Rotation Axes: Check which directions the item is allowed to turn during packing. This helps the calculator find the best fit. If an item must stay upright, uncheck the axes that would tip it over.

Max Layers: Check the box and set a number to limit how many layers high this product can be stacked. Leave it unchecked if there is no limit.

No Stacking / Fragile: Check "No stacking" if nothing should be placed on top of this product. Check "Fragile" to flag the item as breakable, which also stops stacking on top of it.

Add Product: Click this button to add more cargo types. You can add as many different products as you need.

Container Selection: Click on a container card to choose your container size. Options include standard and high-cube sizes from 20 to 45 feet, plus refrigerated containers. Pick "Custom Container" if your container is not on the list, then fill in its inside dimensions, max payload, and tare weight.

Best Container Recommendation: Click this button and the calculator will look at all your cargo and suggest the smallest container that fits everything.

Stacking Algorithm: Choose "Simple" for a fast calculation that uses one orientation per product. Choose "Complex" for a more detailed packing method that tries multiple orientations and places the heaviest items first.

Gap Between Items: Enter the space you want between each item inside the container. Use this if your cargo needs breathing room or protective padding. Set it to zero if items can touch.

Weight Distribution Priority: Check this box to place heavier items first, which helps keep the container balanced and stable.

Calculate: Click this button to run the calculation. You will see how many items fit, space and weight usage percentages, warnings, step-by-step math, 3D and 2D views, charts, and a per-product breakdown table.

Start New Calculation: Click this button to clear all inputs and results so you can begin a fresh calculation from scratch.

What Is Container Loading?

Container loading is the process of fitting cargo — boxes, crates, sacks, or other goods — into a shipping container. Shipping containers are large metal boxes used to move products by truck, train, or ship. They come in standard sizes like 20-foot, 40-foot, and 45-foot lengths. Each container has a set amount of space inside and a maximum weight it can carry, called the payload.

The goal of container loading is simple: fit as much cargo as possible without going over the weight limit or wasting space. When you pack a container well, you ship fewer containers, spend less money, and reduce the chance of damage during transport. To estimate your total shipping costs, you will need to know both the volume and weight of your loaded container.

Why Container Loading Calculations Matter

Guessing how many items fit in a container often leads to problems. You might book too many containers and pay for empty space. Or you might book too few and leave cargo behind. A container loading calculation solves this by using the exact dimensions and weight of your products to figure out how they fit inside a specific container type.

Two key numbers to watch are space utilization and weight utilization. Space utilization tells you what percentage of the container's volume your cargo fills. Weight utilization tells you how close you are to the container's weight limit. A good load plan keeps both numbers high without exceeding the maximum payload. Once you know your load plan, you can determine your freight class and get accurate rate quotes from carriers.

Key Container Loading Terms

CBM (Cubic Meter) — The total volume of your cargo measured in cubic meters. This is the standard unit used in global shipping. Use our CBM Calculator to quickly find the cubic meter volume of individual items or entire shipments.
Tare Weight — The weight of the empty container itself. This does not count toward your cargo weight, but it matters for road weight limits.
Payload — The maximum weight of cargo a container is allowed to hold.
Volumetric Weight — Carriers sometimes charge by volumetric weight instead of actual weight, especially for light but bulky cargo. This is calculated from the dimensions of your shipment.
Stacking — Placing items on top of each other inside the container. Fragile goods often cannot be stacked.
High-Cube Container — A container that is about one foot taller than a standard container, giving extra vertical space for lightweight but bulky cargo.
Refrigerated Container (Reefer) — A container with built-in cooling, used for food, medicine, and other temperature-sensitive goods. Reefers have slightly less inside space because of the cooling unit.
Freight Density — The weight of cargo per unit of volume, often expressed in pounds per cubic foot. Our Freight Density Calculator can help you determine this value, which carriers use to assign shipping rates.

Tips for Efficient Container Loading

Place heavy items on the bottom and lighter items on top. This keeps the load stable and protects fragile goods. Spread weight evenly from front to back so the container does not tip during transport. If your products come in different sizes, mix orientations to fill gaps and use more of the available space. Even a small gap between every item adds up, so keep spacing tight when your cargo allows it.

Before finalizing your load plan, use a freight calculator to compare the cost of different container sizes. Sometimes splitting cargo across two smaller containers is cheaper than using one large one. Also factor in your lead time to make sure your containers are loaded and shipped on schedule. For parcel-sized shipments that do not fill an entire container, check rates with our UPS, FedEx, or USPS shipping calculators instead.

Formulas used

Maximum items fitting in one orientation

n = \left\lfloor \frac{L_{\text{cont}}}{d_x + g} \right\rfloor \times \left\lfloor \frac{W_{\text{cont}}}{d_y + g} \right\rfloor \times \left\lfloor \frac{H_{\text{cont}}}{d_z + g} \right\rfloor

Container volume

V_{\text{container}} = \frac{L \times W \times H}{10^{9}} \quad (\text{m}^3)

Total cargo volume (CBM)

V_{\text{cargo}} = \frac{\sum_{i} (dx_i \times dy_i \times dz_i)}{10^{9}} \quad (\text{m}^3)

Space utilization

U_{\text{space}} = \frac{V_{\text{cargo}}}{V_{\text{container}} \times N_{\text{containers}}} \times 100\%

Weight utilization

U_{\text{weight}} = \frac{W_{\text{cargo}}}{W_{\text{payload}} \times N_{\text{containers}}} \times 100\%

Remaining volume

V_{\text{remaining}} = V_{\text{container}} \times N_{\text{containers}} - V_{\text{cargo}}

Frequently asked questions

What container sizes does this calculator support?

The calculator includes 20-foot, 30-foot, 40-foot, and 45-foot containers in both standard and high-cube heights. It also has 20-foot and 40-foot refrigerated (reefer) containers. If your container is not on the list, pick Custom Container and type in your own inside dimensions, payload, and tare weight.

What is the difference between Simple and Complex stacking modes?

Simple mode picks the single best orientation for each product and packs it that way. It runs fast. Complex mode tries multiple orientations for each item and places the heaviest items first. It usually fits more cargo but takes a bit longer to run. Use Complex mode when you have mixed cargo sizes and want the tightest possible pack.

Can I load different product types into the same container?

Yes. Click Add Product to create as many different cargo types as you need. Each product gets its own size, weight, quantity, color, and packing rules. The calculator packs all of them together into the same container or containers.

How does the Best Container Recommendation work?

When you click Best Container Recommendation, the tool adds up the total volume and weight of all your cargo. It then checks every built-in container size and picks the smallest one that fits everything at about 85% packing efficiency. If no single container is big enough, it suggests the largest container and tells you how many you need.

What does space utilization mean?

Space utilization is the percentage of the container's inside volume that your cargo fills. For example, 75% means your cargo takes up three-quarters of the available space. A higher number means less wasted space and a more efficient shipment.

What does weight utilization mean?

Weight utilization is the percentage of the container's maximum payload that your cargo weight uses. If a container holds up to 28,000 kg and your cargo weighs 21,000 kg, weight utilization is 75%. You must stay at or below 100% to avoid overloading.

What happens if my cargo does not all fit?

The calculator will load as many items as it can and show the rest as unloaded. You will see a warning that lists which products and how many pieces did not fit. To fix this, you can increase the number of containers, pick a larger container, or reduce your cargo quantity.

How do I stop items from being stacked on top of each other?

Check the No Stacking box on that product card. The calculator will not place any other item on top of it. You can also check Fragile, which does the same thing and adds a visual tag to remind you the item is breakable.

What does the Gap Between Items setting do?

This adds a fixed space between every item in the container. Use it when your cargo needs padding, airflow, or protective wrapping. The gap is applied on all sides of each item. Set it to zero if your items can sit right next to each other.

How do rotation axes work?

Rotation axes control which ways the calculator is allowed to turn an item when trying to fit it. If all three axes are checked, the item can be placed in any orientation. If your cargo must stay upright — like a drum or a TV — uncheck the axes that would tip it on its side.

What does Max Layers do?

Max Layers limits how many of the same product can be stacked on top of each other. For example, setting it to 2 means that product can only go two layers high. This is useful for items that can handle some stacking but not too much weight on top.

Can I export or print my results?

Yes. Click Export as CSV to download a spreadsheet file with all your results. Click Print Results to open a print-friendly page you can send to a printer or save as a PDF. Both options include the product breakdown, utilization numbers, and load summary.

How do I use the 3D visualization?

Drag with your mouse to rotate the view. Scroll to zoom in or out. Use arrow keys to orbit and +/- to zoom from the keyboard. You can also select a specific product from the Highlight dropdown to make only that product fully visible. Click Reset Camera to go back to the default view angle.

What is the Toggle Shell button for?

Toggle Shell turns the container outline on or off in the 3D view. Turning it off makes it easier to see the cargo inside, especially when the container is nearly full.

Does this calculator account for pallet dimensions?

There is no separate pallet input, but you can include the pallet in your item dimensions. Add the pallet height to your product height and use the pallet length and width as the item length and width. This way the calculator treats each palletized unit as one box.

What units can I use for dimensions and weight?

For length, you can choose millimeters, centimeters, meters, inches, or feet. For weight, you can choose kilograms or pounds. Pick your units at the top of the calculator before entering any numbers. All inputs and results will use the units you select.

Why does weight distribution priority matter?

When you check Weight Distribution Priority, the calculator places the heaviest items first, starting at the bottom of the container. This keeps the center of gravity low, which makes the load more stable during transport and reduces the risk of tipping or shifting.

What is a refrigerated container and why is it smaller inside?

A refrigerated container, or reefer, has a built-in cooling unit to keep cargo cold. That cooling equipment takes up space inside the container, so the usable loading area is smaller than a standard container of the same outside length.

How accurate is the packing result?

The calculator uses a guillotine-based bin packing algorithm that gives a strong estimate of how items fit. Real-world results may vary slightly because of irregular shapes, packaging bulge, or manual loading methods. The result is a close approximation, not an exact physical guarantee.

Can I calculate loading for more than one container at a time?

Yes. Set the Number of Containers field to more than one. The calculator will fill the first container, then move leftover items into the next container, and so on. You will see a per-container breakdown showing what went into each one.

What is tare weight and do I need to enter it?

Tare weight is the weight of the empty container itself. For built-in container types, the tare weight is already set. You only need to enter it if you choose Custom Container. Tare weight does not reduce your payload, but it matters for total road or rail weight limits.

What does the Calculation Name field do?

It lets you give your calculation a label, like an order number or shipment name. This name shows up on the results page and in exported files so you can tell different calculations apart. If you leave it blank, the tool creates a random code for you.

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