Auto fill with drop down box

Im trying to create a form where you select a product from a drop down list, which will auto fill cells with ingredients which make up that product, and show a total value of how much of each ingredient is needed to make up that product.

the problem im having is that some products are made of the same ingredients but at different % so the values need to adjust based on what % of each ingredient makes up the product.

For example if i wanted to make 500 litres of product 1 id select product one it will fill the cells with the ingredients needed and how much of each ingredient.