A layer cake (according to Moda) is typically 42 pieces of 10x10" each. When sewn, the finished size of each square is 9.5". You have 2 layer cakes, or 84 pieces, so you have 84x9.5x9.5 square inches (7581 square inches) if you plan on just sewing the squares together. It will be less if you intend to cut them into smaller pieces before sewing them together. Without knowing the width of your batting, or the configuration of your quilt, that's all I can tell you.