How can a cosmetologist measure a client's hair growth?

Taking regular length measurements after haircuts is the most effective way for a cosmetologist to measure a client’s hair growth. This method provides quantifiable data, allowing the stylist to track how much hair has grown over a specified period. By measuring the hair length at regular intervals, a cosmetologist can accurately determine the growth rate and make informed decisions about future haircuts, styles, or treatments based on that growth.

Other options are less effective for measuring hair growth specifically. Comparing styles used does not provide an objective measure of length or growth; rather, it focuses on aesthetics. Observing hair texture and noting color changes might indicate the health or condition of the hair but do not provide concrete evidence of growth levels. Thus, regular length measurements are key to tracking hair growth accurately.