What is hair density?
Hair density is how many hairs grow on your head, and how close together they sit. People with high density have a lot of strands packed tightly, so their scalp is hard to see. People with low density have fewer, so their scalp shows more easily, especially along a part.
Density is one of three things people usually mean when they say hair is “thick” or “thin”:
- Density: how many strands you have. This test checks it.
- Strand thickness: how wide each strand is. Our strand thickness test checks that.
- Curl pattern: how much each strand bends. Our hair type quiz covers it.
They are separate. You can have lots of fine strands, or a modest number of coarse ones, and the two can look similar from a distance.
How the test works
You answer four questions about what you can see and feel: how easily your scalp shows, how your ponytail compares, how long your hair takes to dry and how much sectioning it needs. Your scalp counts most, then your ponytail, then the other two. Answers that point both ways are settled toward medium, which is the most common result, and the result says how clearly your answers agree.
The weights are ours. A stylist counting strands in a small square of scalp would be more precise, and the result is a description, not a measurement.
Getting a fair read
- Dry and down. Wet hair clumps together and shows more scalp than it really has.
- Good light, not harsh light. Bright light from directly above makes almost anyone’s scalp look visible.
- Look in more than one place. Density is often a little lower at the temples and the crown than in the middle of the head.
- Compare with yourself. If you have photos from a few years ago, look at those too. That tells you more than comparing with friends.
What suits each density
Low density. Light, volumising products tend to work better than heavy creams and oils, which flatten the hair and show more scalp. Some layering and a part you change now and then help. Many people with low density prefer shorter or mid-length cuts, which look fuller.
Medium density. Most cuts and products suit you. Choose by your strand thickness and curl pattern instead.
High density. Wash, condition and detangle in sections so products reach every strand. Air drying takes longer, and many people with high density find that thinning out the weight, or longer layers, makes hair easier to manage.
Whatever your density, the American Academy of Dermatology’s everyday advice applies: shampoo the scalp, condition after washing, use a wide-tooth comb and limit heat.
Low density or hair loss?
Low density is a description, and many people have had it all their lives. A change is different. The American Academy of Dermatology notes that female pattern hair loss often shows first as a widening part or a thinner ponytail, and that treatment works best when it starts early.
If your part has widened, your ponytail has shrunk, or you can see more scalp than you used to, see a dermatologist rather than relying on this test. Our hair loss doctor checklist helps you decide when.
See your density zone by zone in the HairLens app
The HairLens app scores density zone by zone from photos taken at five angles, and tracks it from month to month, so you can tell a naturally low-density head of hair from one that is changing.