You can use short code [weight]
[weight] ⇒ will get replaced with the total weight of the cart

E.g: 2 * [weight]

E.g: - 2 * [weight]

E.g: 2 * ([weight] - 10)

You can use short code [subtotal]
[subtotal] ⇒ will get replaced with the subtotal of the cart

E.g: 2 * [subtotal]

E.g: - 2 * [subtotal]

E.g: 2 * ([subtotal] - 10)

You can enter fixed amount or make it dynamic using below parameters:
   [qty] ⇒ total number of items in cart

   [fee percent="10" min_fee="20"] ⇒ Percentage based fee

Below are some examples:
   i. 10.00 ⇒ To add flat 10.00 shipping charge.

   ii. 20.00 * [qty] ⇒ To charge 20.00 per quantity in the cart. It will be 100.00 if the cart has 5 quantity.

   iii. [fee percent="10" min_fee="20"] ⇒ This means charge 10 percent of cart subtotal, minimum 20 charge will be applicable. If the 10% is 10$ which is less then 20$ so this will apply a 20$ instead of $10

   iv. [fee percent="10" max_fee="20"] ⇒ This means charge 10 percent of cart subtotal if the 10% is grater then 20 will be applied.

You can enter fixed amount or make it dynamic using below parameters:
   [qty] ⇒ total number of items from the particular shipping class in cart

Below are some examples:
   i. 10.00 ⇒ To add flat 10.00 shipping charge.

   ii. 20.00 * [qty] ⇒ To charge 20.00 per quantity in the cart. It will be 100.00 if the cart has 5 quantity.

   iii. 2 * ( [qty] - 1 ) ⇒ This will charge extra 2 for every extra quantity added from this shipping class after 1 unit (it wont add extra 2 charge when user only have 1 unit of product from this class, but for every extra unit after 1 will be charged extra 2$

You can use short code [qty]
[qty] ⇒ will get replaced with the qty of the product in the cart

E.g: 2 * [qty]

E.g: - 2 * [qty]

E.g: 2 * ([qty] - 10)