Here are a few sample layouts to give you an idea of the number of soakers you can get from different amounts of fleece.
3 XL on 2/3 yd of 58" wide fleece.

5 larges and a small on a yard of 58" wide fleece.

2 larges and a small on 1/2 yd of 58" wide fleece.

7 mediums on a yard of 58" wide fleece.

4 mediums on 2/3 yd of 58" wide fleece.

3 mediums on 1/2 yd of 58" wide fleece.