You can't determine the number of ounces in 18 baguette slices without knowing the size of the baguette. Here's why:

* Baguettes vary in size: A small baguette might be 12 inches long, while a large one could be 24 inches.

* Slice thickness impacts weight: A thin slice will weigh less than a thick slice.

To figure out the ounces, you'd need:

1. The weight of the whole baguette: Look for the weight information on the packaging or ask the bakery.

2. The number of slices: Count how many slices the baguette yields.

Then, you can calculate:

* Ounces per slice: Divide the baguette's weight (in ounces) by the number of slices.

* Total ounces: Multiply the ounces per slice by 18.

Let me know if you have the baguette's weight, and I can help you calculate the ounces!