Combining shipping rates
I imagine you have the need for a setup with something like;
– Each product of shipping class A costs $1.50 to ship
– Each product of shipping class B costs $2.50 to ship
A question that is being asked with some frequency is how to combine different shipping rates as shown on the right to show as one price. Short answer, this is not possible (but do read on).
How shipping rates work
Each shipping method you create will be displayed as a separate option to the customer if they meet the criteria set in the conditions. In the screenshot above there could be as much as 7 shipping rates displayed at the checkout, as long as the conditions all match to the customer. These shipping rates won’t merge together.
How to setup separate shipping cost per product (shipping class/category)
In order to setup a separate cost per product, shipping class, category you are looking for the extension WooCommerce Advanced Shipping – Advanced Pricing, which extends WooCommerce Advanced Shipping.
That extension will allow you to add extra cost based on the selected pricing option. It adds a section below the regular shipping settings ready for you to get started.
In the link above you will find out a more extensive documentation about this extension and how to get it.
Update
A new doc is created on how to add shipping cost / conditions to another shipping rate. If its possible to use the WAS Advanced Pricing extension mentioned above, its recommended. Otherwise, read on here: How to apply conditions / cost to another shipping method.