If the fabric is aida cloth, you will see a grid on the back of the fabric. The squares in this grid are equal to the squares in the chart. For example, if the chart has a 10 by 10 grid and the fabric has a 10 by 10 grid, then each square in the chart will represent a square in the fabric. If the fabric is not aida fabric, you will need to count the squares in the chart and then count the squares in the fabric.