The types of hairlines that are considered normal vary by both age and gender. On a female, a normal hairline forms an upside down U and is located approximately 2 inches (5 cm) to 2.4 inches (6 cm) above the eyebrows. Many female hairlines are slightly irregular and form a Widow's Peak, or forward triangle, toward the middle of the forehead. A normal hairline for a mature male should form a U-shape and begin 2.4 inches (6 cm) to 3.2 inches (8 cm) above the eyebrows. People who have a high, low or abnormal hairline can undergo different treatments to change the shape or height of their hairline.

While the normal female hairline should resemble an inverted U, most females have sightly irregular hairlines. These irregularities are due to changes in the hair’s growth pattern, called whorls or cowlicks. It is also normal for women to have a Widow’s Peak, which occurs when the hair forms a small triangle toward the middle of the forehead. Unlike men, a woman’s hairline should not recede toward the temples. While asymmetry is very common, a hairline that looks as if it might be receding is not considered normal in women.

In women, the height of the hairline is also important. A high hairline, located more than 2.4 inches (6 cm) from the eyebrows, can enlarge the forehead and make a woman appear older. Low hairlines might also appear abnormal. Very low hairlines can make the forehead appear small and unbalanced.

For an adult male, a normal hairline is one that forms a forward U. Men are less likely to have a Widow’s Peak or other irregularities due to whorls or cowlicks. After puberty, a male’s hairline will recede between 0.8 inches (2 cm) and 1.6 inches (4 cm) at the temples and 0.4 inches (1 cm) to 0.8 inches (2 cm) toward the middle of the forehead. This is the natural progression of a man’s hair and does not mean that he is balding.

While it is common for men to lose their hair, a thinning or drastically receding hairline is not considered normal. Receding is usually first noticeable at the temples. As more hair is lost, the hairline will begin moving higher onto the crown of the head.

People who want to fix a receding or abnormally high hairline can do so by getting hair transplants. During a hair transplantation procedure, a dermatological surgeon will transfer hair from one area of the head to another. Medicated shampoos and ointments can also be used to slow hair loss and restore the hairline with varying success.

Excessively low hairlines can also be made to look more normal. One way to do this is to remove hair from the hairline. Unless a person’s hair is thinning, any abnormalities can also usually be disguised by wearing bangs or short layers around the face. This will create the appearance of a normal hairline without having to frequently remove hair from the area.