Counting Unique Values

Hi all,

I'm building a spreadsheet that will allow me to calculate the charges for an e-commerce client I provide 3PL services to.

The charges are partly based on the number of unique products (regardless of the quantity of that product) I pick for each order.

My spreadsheet has a tab with all the orders I pick; each row contains an order number and a product (i.e one order may be split across several rows if there are multiple products in the order).

I'd like to create another table/tab that counts the number of unique products for each order number and multiples the result by a set rate (perhaps defined in another table).

Can any one help? It will be much appreciated!

Thanks