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Carrier Calculated shipping overview

Carrier Calculated shipping automatically calculates shipping rates based on rates from multiple carriers. Squarespace uses a package's weight, dimensions, and the shipping address to group items into your preferred containers and present customers with accurate shipping rates at checkout.

Current supported carriers:

  • FedEx
  • UPS
  • USPS
Carrier Calculated shipping is available on the Advanced plan, and certain legacy billing plans.

Before you begin 

  • Carrier Calculated shipping doesn't create shipping labels. Consider connecting your site to ShipStation, a service that batch-prints shipping labels with major carriers.
  • Carrier Calculated shipping is only available for domestic shipping within the United States.
  • Carrier Calculated shipping doesn't reflect negotiated rates with your carrier. 
  • If Carrier Calculated shipping is enabled, the item limit in shopping carts reduces to 150 items. (The default limit is 500 items.) This limit is in place to keep shipping estimates accurate, since larger orders interfere with providers' shipping algorithms.
  • This guide shows how to set up your store for Carrier Calculated shipping. For provider-specific instructions, visit our USPS, FedEx, and UPS shipping guides.

Step 1 - Add dimensions to items

Carrier Calculated shipping groups items into containers (the boxes you mail orders in) to find the best shipping rates. To ensure shipping estimates are accurate, it's important to add dimensions and weights to all your products, accounting for any item-specific packing materials.

Note: Weight and dimensions should cover the product when it's boxed for shipping, not the item's dimensions as-is which might be different than the product's actual dimensions without packaging.
For example, a poster is 24" x 36" laid flat, but when shipped in a poster tube, its dimensions are 3" x 36". Use the poster tube dimensions to calculate shipping costs.

To add dimensions and weight to a product, open a product for editing and click the Pricing & Variants tab. Click the Weight and Dimensions fields and enter values. Complete this for all variants. These dimensions won't be visible to customers.

Enter weight and dimensions for all physical products to prevent issues at checkout.

Step 2 - Add a shipping option

In the Home Menu, click Commerce, and then click Shipping.


Click Add Shipping Option.

Select a Carrier Calculated shipping option:

Step 3 - Set a formula

In the Formula tab, check the carrier services you want to enable. Carrier services are different offerings and shipping speeds that carrier offers — you don't need to support every service. Available services vary by provider.

We recommend being selective with your shipping options to avoid overwhelming customers and speed up the checkout process.

Tip: We recommend communicating your processing time to your customers. If you don't process orders daily, or multiple times throughout the day, including a note about average process time will help set your shoppers' expectations.

Next enter a Markup percentage and shipping ZIP Code.

  • Markup - Enter a percentage or amount markup to charge more than the estimated cost. This is a useful way to cover the price of packaging, time spent shipping, or other additional costs.
  • Ship from ZIP Code - Enter the ZIP Code for your shipping origin. If you ship products from your home or store location, this should be your ZIP Code.
Note: USPS offers discounted rates for merchants who print their own labels. For more information on Online Pricing, visit USPS Carrier Calculated shipping.


Step 4 - Add containers

You can enable standard carrier containers or add your own custom containers. Some services aren't compatible with standard containers, so check the provider-specific guide for further information.

At checkout, each product's dimensions helps group the order into the fewest containers. This gives your customers the best rates.

Note: Since customers may purchase multiple items, it's important to set containers larger than your product dimensions. If your containers are set to accommodate one item each, this packages large orders in multiple containers and significantly increases shipping costs.

Carrier containers

Depending on the services enabled, you'll see a list of your carrier's standard containers. For more information, visit the carrier-specific guides:

Custom containers

In the Custom Containers tab, click Add a custom container. Enter a Container name and its Dimensions. Click the icon to add more containers.

When you're done adding containers and editing your formula, click Save.

Note: You'll see an error if your container is larger than the package sizes offered by your carrier. To resolve this, see Shipping oversized items.


Step 5 - How carrier calculated rates appear at checkout

At checkout, Carrier Calculated shipping uses the dimensions for all items in an order to find optimal packing. If there are multiple options, customers can compare pricing and select the best option.

Step 6 - Fulfilling an order with Carrier Calculated shipping

This section explains how Carrier Calculated shipping affects live orders.

Open the order

When you receive an order, click an order to open the Order Summary

Shipment overview

Click the Shipment tab. Here, you'll find a summary of the customer's shipping information, including:

  • The provider service selected
  • Number of packages required (Squarespace estimates the lowest quantity possible based on the dimensions of the items in the order)
  • Quantity of items in the package
  • Total weight of the order

Select a package

If the order requires multiple packages, you'll see each package appear when you click in the Select a Package drop-down menu.

If an item doesn't fit into the containers you offer, you'll see Item Packed Separately.

Packing configuration

The Packing Configuration shows a 3D rendering of the selected package with the item, dimension, and weight for each package. Your actual package may look different. This is an approximation.

Step 7 - Check rates

Rates are calculated based on the dimensions and weight of the package and the distance shipped. To test how rates for different product combinations are calculated, run test orders.

Running a test order will show you how items are being placed in their containers. If the rates seem high, check them against the provider's rate calculator:

You can often reduce rates by creating a new custom container or reducing the dimensions of a product so it fits the container better.

Tip: If you run a test order and have questions about how the shipping price was calculated, open a ticket with the following information:
  • Exact products in the cart
  • Shipping options selected
  • Exact address used
  • Order # for any relevant test orders

Shipping oversized items

To ship items that exceed your carrier's package sizes or weight limits, add another shipping rule using Depending on Weight or Flat Rate Shipping

For more tips, visit Selling large or heavy products.

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Carrier Calculated shipping overview