Help with Formula for Customized Calculator

Hello!

I am in the process of creating a custom calculator. I have a list of items that we use at my job and their weights next to each corresponding item. I've already created the dropdown list of the items using data validation. What I need assistance with is how to create a formula that will allow me to figure out the total weight of items depending on which item on the dropdown list was chosen.

For example, if "Bath Blanket (white)" was chosen, then the value would be the weight of one bath blanket multiplied by whatever number they enter in the cell next to the dropdown. Let's say the bath blanket weighs 660g and they enter 2 in the cell next to the dropdown list... I want the "Total Weight" cell to be 1,320g.

Help!