What is Cartonization?

Deciding what package to use to ship an order has big consequences. It impacts that time your staff spends fulfilling each order and it impacts the total cost of a shipment. Cartonization is a way to automate this process. But what exactly is cartonization?


Tyler Douglas

When fulfilling and shipping orders, efficiency is key. Cartonization, a process often overlooked, plays a vital role in this efficiency. It involves determining the most suitable type of packaging for shipping items while minimizing space and cost. This post explores the concept of cartonization and the complexities involved in creating an effective cartonization algorithm.

What is Cartonization?

Cartonization is the process of determining the optimal package size and type for a given set of items, considering factors like weight, dimensions, fragility, and the best fit. The primary goal is to minimize shipping costs and material usage while ensuring the safety and integrity of the items.

Challenges in Developing Cartonization Algorithms:

1. Complex Calculations:

Volume Utilization: 

Maximizing space without overstuffing is a delicate balance. The algorithm must calculate the best way to fit items into boxes, considering their shapes and sizes.  Items can deform meaning that in different orientations they can occupy more or less space.

2. Diverse Product Attributes:

Variability in Size and Shape: 

Products come in various sizes and shapes, making standardization difficult. The algorithm must be versatile enough to accommodate this diversity.  Things like cups can be stacked inside of each other to minimize volume while bottles must be placed next to each other.

Handling Requirements:

Some items may be fragile or require specific orientations. The algorithm needs to account for these special handling requirements. If a special package type is needed to accommodate an item, the algorithm must adapt and only consider packages that meet the specifications.

3. Cost Considerations:


The package you choose impacts the shipping service, a good cartonization algorithm should aim to minimize the overall shipping cost that the package entails.

For example, if a flat-rate shipping option comes with a free package but costs $0.50 more than a standard rate option when including the cost of the package, the algorithm should choose the lower cost option. 

How String Approaches Cartonization

String is a plug-in for ShipStation with the most robust cartonization algorithm in the world.  Unlike other cartonization algorithms, String can take into account things like deformability to determine the optimal package size. 

Additionally, String does shipping cost aware comparison to make sure that the package selected always results in the lowest cost shipping. 

If you use ShipStation, you can be up and running with String in as little as 15 minutes to start having your orders automatically updated with the right size package option. 

From there, you can also use String to rate shop with the selected package and apply it to your packing slips so your fulfillment staff can save time deciding what package to use for every order. 

Get your free savings analysis from String!