Hair comes in all sorts of colors and styles. It can also be categorized in many ways, depending on hair type. For example, hair type can be determined by curl patterns — for example, wavy, straight, curly, etc.
Hair density is another way hair is categorized. But what is hair density exactly? And how is it measured? Most people automatically assume that hair density refers to the thickness of the hair.
However, there is more to it than that. In this article, we’ll take a look at hair density, what it is, and some quick and easy ways that you can measure it.
Table of contents:
- What Is Hair Made Of?
- Knowing Your Hair Type
- What Is Hair Density?
- Hair Density vs. Hair Thickness
- Hair Density vs. Hair Texture
- Hair Density vs. Hair Porosity
- How Can You Measure Your Hair Density?
What Is Hair Made Of?
Before we dive into hair density, it’s important to take a wider look at the hair and all its components. Hair is often thought to be merely an element of style and expression. While that is certainly true, that role is secondary.
Primarily, hair plays a protective role against environmental factors like UV exposure and weather. That’s why it’s so important to keep it healthy.
Healthy hair starts at the root — literally. The hair root rests within the hair follicle, which lies right beneath the skin. The hair shaft is what we see on the scalp.
A hardening protein called keratin is the primary force behind hair growth and formation. The hair shaft is made of three keratin layers: medulla, cortex, and cuticle.
- Medulla: The innermost layer of the hair shaft is called the medulla. This layer is usually only present in thicker hair types. It consists of a thin, soft core of air spaces and transparent cells.
- Cortex: Next is the cortex. This middle layer makes up most of the majority of the hair shaft. It also contains pigment cells, which are responsible for your hair color.
- Cuticle: The outermost layer of the hair shaft is called the cuticle. This layer has a protective role and is composed of overlapping cells, sort of like shingles on a roof.
Knowing Your Hair Type
When it comes to hair care, knowing your hair type is absolutely essential, not only for hair health but also for styling and choosing the right hair care products. When most people think of hair type, they are referring to the shape of a person’s hair. However, curl pattern also plays a large role in hair type.
Hair types are categorized into four types:
- Type 1 (Straight hair)
- Type 2 (Wavy hair)
- Type 3 (Curly hair)
- Type 4 (Coily hair)
Hair type, along with hair density, is determined by your genetics, which is the DNA structures that are inherited from your parents. They also determine other physical attributes (also called phenotypes) like eye and hair color, height, and blood type.
Your hair type will also play a role in other important factors. For example, hair type determines how much natural hair oil or sebum you’re likely to have. Hair oil production in and of itself is very important when it comes to hair care routines.
There are other important factors to consider when trying to determine your hair type. These include hair texture, hair porosity, hair elasticity, and hair density.
What Is Hair Density?
On average, most healthy men and women have roughly 80,000 to 120,000 strands of hair on their scalps. Most people shed around 100 of these per day.
There tends to be a lot of confusion when it comes to hair density. Many people use hair density synonymously with hair thickness. While there may be some overlap, these are not the same thing.
Density is not determined by the thickness of the hair shaft; density is determined by the amount of hair covering a given space. In simple terms, hair density refers to the number of hair strands per square inch of your scalp or how closely your hair fibers grow together.
As mentioned above, the density of your hair is affected by your genetics. Another factor that determines how tightly your hair is packed together is hair texture.
In general, there are three categories of hair density: Low density, medium density, and high density.
- Low-density hair: Hair fibers that are sparsely placed can be considered low-density. This can simply mean there are fewer hair strands.
- Medium-density hair: Those with medium-density hair fit somewhere in between low and high density. Styling tends to come easiest to those with medium-dense hair.
- High-density hair: With high hair density, the strands are tightly packed together. This is typically more common among those with thicker hair types.
Hair Density vs. Hair Thickness
While hair density refers to the number of hair strands per square inch, hair thickness refers to the actual thickness of a single strand of hair.
The average thickness of a strand of hair is roughly .06 to .04 millimeters wide. To put that in perspective, the tip of a pencil is about seven millimeters.
Hair thickness is determined by keratin amount — which is about 80% of the strand, water content (10 to 15 percent), and lipids (five to 10 percent).
The thickness of your hair is set in place — again, by your genetics. However, proper hydration can help your hair appear thicker. This can be done using hair oils, deep-conditioning hair masks, and hydrating shampoos and conditioners.
Hair Density vs. Hair Texture
Hair density is also different from hair texture. Texture refers to both the thickness and form of the individual hair strands.
The texture of a person’s hair will determine how easy or difficult it will be to manage, style, and care for. It is typically defined in three ways: fine, medium, and thick (or coarse).
- Fine hair is considered the most fragile hair texture. It is also harder to style and is more susceptible to damage from some hair care products. Fine hair is also typically thin.
- Medium hair textures are more resistant to damage and breaking than finer hair textures. Medium hair texture is the most common hair texture.
- Thick hair texture tends to be the most tolerant of hair care and styling products. It is also the least likely to break.
Hair Density vs. Hair Porosity
Hair porosity also differs from hair density. Porosity refers to how well your hair retains or absorbs moisture.
Porosity is affected by the cuticle, the outermost layer of the hair shaft that was mentioned above. Porosity is defined in three categories: low, medium, and high.
- Low porosity hair is marked by layers that are close together, making it harder for water to saturate your hair when washing.
- Medium porosity hair is considered normal. The layers are neither too tight nor too open, which means that moisture is able to penetrate more easily. Medium porosity tends to have a healthy look or shine.
- High porosity hair allows moisture to penetrate easily, but it is unable to retain the moisture very well. This is due to gaps within the layers. This type of hair porosity tends to break more easily.
How Can You Measure Your Hair Density?
As mentioned above, hair density is about the number of individual strands you have in a square inch of an area on your scalp, not the actual thickness of the hair strand. Measuring your actual hair density can give you a better understanding when it comes to hair care and styling.
There are a few different ways you can measure your hair density. Some are quick and easy DIY solutions, while others may involve some professional help from a hairstylist or trichologist (a specialist with a focus on hair and scalp issues). Let’s take a look.
The Ponytail Test
One of the easiest and most common ways to measure hair density is the simple ponytail test. While it is not an exact science, it can give you a better idea of where you fall when it comes to hair density: low, medium, or high.
Here are the quick and easy steps:
- Make sure to smooth out your hair as much as possible, either with a comb or your fingers. Also, make sure you’re working with dry hair.
- Gather your dry hair and tie it into a ponytail.
- Next, you’ll need to measure the circumference of your ponytail — you can do this by looping a piece of ribbon around your ponytail.
- Place the ribbon next to a ruler to get the exact measurements.
If your measurement is less than two inches, then it is likely that you have low hair density. Medium-density hair is around two to three inches in circumference. Beyond four inches is considered high-density hair.
The Scalp Test
The scalp test is another way you can measure your hair density. Before you get started, make sure to give your mane a good wash.
Let your hair air dry and let it loose. Also, make sure to avoid gels, creams, and hair products. Now, it’s time to take a look in the mirror — literally.
You’re going to be inspecting your hair roots and scalp. Tilt your head slightly to examine your scalp. If you can see your scalp easily (without parting or sectioning), then you likely have low-density hair.
If you’re unable to see much of the scalp at all, then you probably have high-density hair. Medium density would be somewhere in the middle.
You Can Count ‘Em — No, Seriously
If you aren’t satisfied with the ponytail or scalp tests, you can literally resort to counting your hair strands. If it doesn’t sound fun, it’s because it’s not. But it will give you an accurate number.
Now, this doesn’t mean you need to carve out half the day to count every single strand of hair on your head — choosing one square inch to focus on will do the trick. But be advised average person has around 2,200 hairs per square inch. Enjoy.
Get Help From a Professional
If you’re looking to go beyond the DIY tests — or you don’t feel like counting — you can always consult a professional. They can use non-invasive techniques to help give you an accurate idea of your hair density. These techniques are typically performed by a trichologist.
For instance, a trichoscopy is an imaging test that provides high magnification of your scalp and hair strands to help quantify your hair density. A phototrichogram is another technique that is very similar to the trichogram, but it is typically less common.
Knowing your hair type and type of hair density is an important first step when it comes to choosing the right products and styles, but also for establishing a healthy hair care routine. Check out WOW for hair care products to fit any hair density.
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