A factor that denotes band shape. The asymmetry factor is calculated from the chromatographic peak by dropping a perpendicular at the peak apex and a horizontal line at 10% of the peak height; at the intersection, the distance to the tail of the peak along the horizontal line (distance B) divided by the distance along the horizontal line to the front of the peak (distance A) produces a ratio called the peak asymmetry factor. The ratio is 1 for a symmetrical peak, less than 1 for a fronting peak, and greater than 1 for a tailing peak. The higher the value, the less symmetrical the peak; values greater than 2 are unacceptable.