What i do is I put my nail along the last line on the mat and move the fabric over. I then remeasure the fabric in front of the 0 line at the beginning to make sure it is still accurate, and measure the remaining portion. I do this if the piece is too long to just half it with a fold on the mat. If you have to move it over a few times you might have to use the 24 inch rule plus another to measure the piece in front of the line.