What term describes the number of hair strands per square inch on the scalp?

The term that refers to the number of hair strands per square inch on the scalp is density. This measurement indicates how many individual hair follicles are present in a given area and is a critical factor in determining how full or thin a person's hair appears. High density means that there are many hair strands packed closely together, giving a thicker appearance, while low density indicates fewer strands and can result in a more sparse look.

Understanding hair density is essential for stylists as it influences cutting techniques, styling options, and product recommendations. For example, hair texture and porosity relate to the characteristics of the hair strands themselves, such as their thickness, consistency, and ability to absorb moisture, but they do not measure the quantity of hair present on the scalp. Counting hair strands or measuring the area of hair follicles focuses solely on density, which is crucial for personalized hair care and styling approaches.