Measurement has value in cosmetology in two ways. When preparing the solution for coloring someone's hair, being able to calculate the volume of various products needed is necessary to get the right mixture. In addition, customers may want a specific amount of hair cut off or want their eyebrows a certain shape. Cosmetologists need the spatial skills to judge these measurements.
Many women's haircuts require an understanding of angles to get the cut to work right. The angle of a cut determines how the hair will lie on the person's head after cutting. Cutting layers into hair requires understanding angles as well. Hair diagrams, such as the one of Dorothy Hamill's haircut on HairFinder.com, are common for cosmetologists to use to determine the right way to cut hair. Reading these diagrams requires a basic understanding of geometry.
Cosmetologists typically are self-employed. Some own their own shops while others work as independent contractors in larger shops. Business math is an understanding of how to calculate the amount a customer owes and what that person's change should be. Basic business math also includes concepts, such as calculating percentages, which allow a cosmetologist to determine the right price for her products.
Accounting for self-employed people means knowing how to determine what expenses are deductible business expenses and how to calculate your tax rate, which will help in setting prices. Understanding how to estimate taxes and which exemptions are relevant is important to helping a cosmetologist run a successful business.