Note: While our most popular guides have been translated into Spanish, some guides are only available in English.

Carrier calculated shipping

Use carrier calculated shipping, also called “real-time rates,” to automatically calculate shipping fees based on FedEx, UPS, and USPS rates. It uses package weight, dimensions, and addresses to determine accurate shipping prices and group orders into the best-fitting packages.

Carrier calculated shipping is available on the Commerce Advanced plan and certain legacy billing plans. It's available for domestic shipping within the United States. It's not available for shipping to Puerto Rico or the US Virgin Islands.

Before you begin

  • This feature doesn't include printing shipping labels. To print shipping labels, connect an extension and choose Easyship, Shippo, or ShipStation.
  • We don’t currently support custom negotiated rates with carriers.
  • If carrier calculated shipping is enabled, shopping carts will have a 150-item limit to keep shipping estimates accurate. Without carrier calculated shipping, the limit is 500 items.

Supported carrier services and containers

Here are the carrier services you can offer through this integration. You can also add custom containers if you ship orders in generic boxes or envelopes.

FedEx services

You can use these FedEx services through this integration. For delivery timing and other information, visit the FedEx's website.

  • FedEx Ground Home Delivery (requires a custom container)
  • FedEx Priority Overnight
  • FedEx Standard Overnight
  • FedEx 2Day
  • FedEx Express Saver
  • FedEx First Overnight

FedEx containers

Services except Ground Home Delivery support the following containers:

  • FedEx® Small Pak 10.25" ✕ 12.75" ✕ 0.25"
  • FedEx® Large Pak 12.00" ✕ 15.50" ✕ 0.25"
  • FedEx® Small Box 10.88" ✕ 1.50" ✕ 2.38"
  • FedEx® Small Box 8.75" ✕ 2.69" ✕ 11.31"
  • FedEx® Medium Box 11.50" ✕ 2.38" ✕ 13.25"
  • FedEx® Medium Box 8.75" ✕ 4.38" ✕ 11.31"
  • FedEx® Large Box 12.38" ✕ 3.00" ✕ 17.50"
  • FedEx® Large Box 8.75" ✕ 7.75" ✕ 11.31"
  • FedEx® Extra Large Box 11.88" ✕ 10.81" ✕ 11.06"
  • FedEx Extra Large Box 15.75" ✕ 14.19" ✕ 6.00"
  • FedEx® Tube 6.00" ✕ 6.00" ✕ 38.00"

UPS services

You can use these UPS services through this integration. For delivery timing and other information, visit the UPS website.

  • UPS Ground
  • UPS Next Day Air
  • UPS Next Day Air Saver
  • UPS 2nd Day Air
  • UPS 3 Day Select

UPS containers

Next Day Air, Next Day Air Saver, and 2nd Day Air support the following standard containers:

  • Small Express Box 13.00" ✕ 2.00" ✕ 11.00"
  • Medium Express Box 15.00" ✕ 3.00" ✕ 11.00"
  • Large Express Box 18.00" ✕ 3.00" ✕ 13.00"
  • Express Tube 38.00" ✕ 6.00" ✕ 6.00

Ground and 3 Day Select require custom containers.

USPS services

You can use these USPS services through this integration. For delivery timing and other information, visit the USPS website.

  • USPS Priority Mail
  • USPS Priority Mail Express
  • USPS Retail Ground

First Class, Media Mail, and Envelope shipping rates aren't available in this integration.

USPS containers

The following flat rate boxes are available for Priority Mail only. For Priority Mail Express or Retail Ground, add custom containers.

  • Priority Large Flat Rate 23.69" ✕ 3.00" ✕ 11.75"
  • Priority Large Flat Rate 12.00" ✕ 5.50" ✕ 12.00"
  • Priority Medium Flat Rate 11.00" ✕ 5.50" ✕ 8.50"
  • Priority Medium Flat Rate 13.63" ✕ 3.38" ✕ 11.88"
  • Priority Small Flat Rate 8.63" ✕ 1.63" ✕ 5.38"

When you choose Priority Mail, these boxes are considered a shipping option by default. If you don't want to offer shipping via USPS flat rate boxes, uncheck Use flat rate boxes.

Step 1 - Add dimensions and weight to all products

Note: We recently updated the product editor, so the steps in this guide might not match what you see on your site. You can switch to the new product editor at any time, or follow the steps in Using the classic product editor if you aren’t ready to switch.

Add dimensions and weights to all products based on how they're shipped. When all products have accurate dimensions, customers’ orders will group into the best-fitting packages with the best rates.

To add dimensions and weight to a product:

  1. Open the product.
  2. Click Advanced shipping.
  3. Add measurements to the Length, Width, Height, and Weight fields. Use measurements that cover how the products are boxed for shipping, including any wrapping and packing materials—not the item’s dimensions as-is.
Tip: For example, a poster is 24" x 36" laid flat. When shipped in a poster tube, its dimensions are 3" x 36". Use the tube dimensions, not the flat dimensions, since it ships in the tube.
  1. Repeat these steps for all products already in your store. When you add new products in the future, complete these steps too.

Fit your products in fewer containers

For large orders, our system groups products into the fewest number of containers. If several products should fit in one container but get placed in two separate containers, decrease your product's length, width, and height by at least one inch. This way, you'll account for package padding and ship your products in fewer containers.

Find products with missing weights and dimensions

The best way to ensure all products have weights and dimensions is to review products in the Inventory panel. After you add a carrier calculated shipping option, products with missing weights and dimensions will display a red arrow. Double click the product to edit it.


Add dimensions to product descriptions (optional)

Dimensions and weights added in the Advanced shipping section aren’t visible to customers. To display products’ dimensions as-is (for example, a poster’s flat dimensions), add them to products' descriptions instead.

Step 2 - Add shipping services and optional markup

Next, use the settings in the Formula tab to help calculate shipping costs.

To set up a carrier calculated shipping option:

  1. In the Home menu, click Commerce, and then click Shipping. You can also use the ? key while any panel is open and search shipping.
  2. Click Add Shipping Option.
  3. Choose a carrier, either UPS, FedEx, or USPS.
  4. In the Formula tab, check the carrier’s services you use. For a list of supported services, see Supported carrier services and containers. You don't need to use every service the carrier offers.
  5. Optional: Below the list of services, enter a percentage or flat amount Markup to charge more than the estimated cost. This is a useful way to cover the price of packaging, handling, time spent, potential margins of error, or other costs.
  6. Enter the Ship From Zip Code based on where you ship orders from. Shipping rates will be calculated based on distance from this Zip Code.

Here’s an example of a Formula tab for USPS rates:


Step 3 - Add containers

Next, add containers, which are the boxes, envelopes, or packages you use to ship orders. We’ll estimate the best shipping rates for orders based on the fewest number of packages and smallest containers possible. You can choose from:

Standard carrier containers

Carrier services offer many standard containers for your shipping needs. For example, FedEx® Small Pak or UPS Small Express Box.

Custom containers

Add custom containers if you use generic boxes/envelopes. You'll need to use custom containers for certain carrier services, including:

  • FedEx Ground Home Delivery
  • UPS Ground and 3 Day Select
  • USPS Priority Mail Express and Retail Ground

For a complete list of supported containers and custom container dimensions, go to Supported carrier services and containers.

Tip: If you're not sure what's best, choose slightly bigger containers than you think you'll need. If containers can only fit one product at a time, the integration will group large orders into multiple packages, which could significantly increase shipping costs.

Add the carrier's containers

To add a carrier's standard containers:

  1. Click the FedEx Containers, UPS Containers, or Flat-Rate Boxes tab, depending on the carrier.
  2. If carrier containers are available for any of the services you chose, check Use FedEx Containers, Use UPS Containers, or Use Flat-Rate Boxes.
  3. Review the containers available for the service, and use the checkbox to confirm you'll use them. For a list of supported containers, see Supported carrier services and containers.
Note: Some services don't use carrier containers. If you choose a service that doesn't have carrier containers, you'll be prompted to add custom containers in the next tab.

Add custom containers

If you use your own boxes or envelopes when shipping with this carrier, add shipping containers with custom dimensions:

  1. In the Custom Containers tab, click Add a custom container.
  2. Enter a Container name and its Dimensions.
  3. Click the + icon to add more containers.
  4. When you're done, click Save to save the shipping option.

You'll see an error if a custom container is larger than the package sizes offered by your carrier. For tips on shipping oversized items, see Selling large or heavy products.

How rates appear at checkout

On the checkout page, shipping options will appear after a customer enters their address. The prices are calculated based on how the items in their order will be packaged (based on weight and dimensions) and their shipping address. If there are multiple options, customers can compare and choose from them.


Run test orders to check rates and packaging

To test how rates for different product combinations are calculated and placed in containers, run test orders.

If rates are higher than expected

If calculated rates in a test or live order seem high, check them against the provider's rate calculator:

You can usually lower the prices by adding custom containers or reducing products’ packing dimensions so they better fit your containers. If you have questions about how a shipping price was calculated in a test or live order, contact us. Include the order number(s) so we can help.

Fulfill an order with carrier calculated shipping

If a customer chose a carrier calculated shipping option at checkout, their order summary includes specific shipment information.

To prepare an order for shipment:

  1. Open the order.
  2. Click the Shipment tab. Here, you'll find a summary of the customer's shipping information. It includes the service the customer chose, number and type of containers you’ll need, number of items in the package, and total weight.


  1. Optional: If the order requires multiple packages, you'll see each container you'll need when you click the Select a Package drop-down menu.
  2. Optional: If an item doesn't fit into the containers you offer, you'll see Item Packed Separately.
  3. Use the Packing Configuration as a reference to help you pack the order. This image is an estimate, and your actual package might look different.


Shipping oversized items

To ship items that exceed your carrier's package sizes or weight limits, using a different shipping option like Depending on Weight or Flat Rate is usually the best solution. For more tips, visit Selling large or heavy products.

Was this article helpful?
48 out of 110 found this helpful
Carrier calculated shipping