While measuring a stone is quick and easy, the process varies from shape to shape. For round shaped stones measure across the widest point.  Turn the stone to make sure your measurement is accurate. For heart shaped stones measure vertically from top to bottom then across the widest part. Measure vertically from the base to the point for triangular or trillion shaped stones.  For square shaped stones first measure vertically then horizontally.  This process includes antique, princess cut,  and square step cut scenes. When measuring a straight baguette, begin vertically then across the widest part of the stone. For tapered baguettes measure vertically then the width of the stone.