Your Hair Type, Explained: Curl Patterns, Porosity, and Density

Curl Pattern: The Shape of Your Strand

Curl pattern is typically the first characteristic people identify — it's the most visually obvious. The widely used numerical classification system sorts hair into four broad categories: Type 1 (straight), Type 2 (wavy), Type 3 (curly), and Type 4 (coily or kinky). Each category is further divided into subcategories — A, B, and C — to reflect the tightness or looseness of the curl or wave.

Type 2A hair forms soft, barely-there waves, while 2C waves are more defined and prone to frizz. Type 3A curls are loose and springy; 3C curls are tight corkscrews. Type 4 hair ranges from soft coils (4A) to densely packed zigzag patterns (4C) that may appear shorter than their actual length due to shrinkage.

It's worth noting that most people have more than one curl pattern on their head — the crown, sides, and nape often behave differently. Evaluating your hair in its natural, unmanipulated state (clean, air-dried, product-free) gives the most accurate picture. For a broader look at how these traits fit into your overall routine, see the full-spectrum hair care guide covering scalp health and styling.

Porosity: How Your Hair Handles Moisture

Porosity is arguably the most important trait to understand when building a hair care regimen. It describes how well your hair cuticle — the outermost, overlapping layer of each strand — opens and closes to absorb and retain moisture.

• Low porosity: Cuticles lie flat and tightly packed. Water and products sit on the surface rather than penetrating easily. Hair may take a long time to get fully wet and even longer to dry. Lightweight, water-based products tend to work better than heavy creams.
• Medium (normal) porosity: Cuticles allow moisture in and hold it reasonably well. This type is the most flexible and generally responsive to a wide range of products.
• High porosity: Cuticles are raised or have gaps, absorbing moisture readily but losing it just as fast. Hair may feel dry or brittle despite regular conditioning. Richer moisturizers and sealants (like oils applied after a water-based product) can help lock moisture in.

If you're constantly applying moisture products but your hair still feels parched, porosity may be the overlooked factor. Our article on why your hair feels dry no matter what you put on it explores this in detail. Similarly, choosing between a standard conditioner and a deep conditioner often depends on your porosity level — something covered in our guide on conditioners vs. deep conditioners vs. hair masks.

Density and Strand Width: Volume and Texture

Density and strand width are two distinct measurements that are often conflated. Density refers to the number of hairs per square inch on your scalp. A simple way to assess it: look at your scalp through your hair. If it's immediately visible without parting, you likely have low density. If you have to search for it, density is probably high.

This matters for product and styling choices. High-density hair holds styles well but can feel weighed down by heavy products. Low-density hair may benefit from lighter formulas and volumizing techniques to avoid limpness.

Strand width (also called texture or coarseness) is about how thick each individual hair is. Fine strands are more fragile and can be overwhelmed by heavy oils; coarse strands are more resilient and may need more intensive moisture treatments to feel soft. You can gauge your strand width by rolling a single strand between your fingers — fine hair is barely perceptible, while coarse hair has a noticeable thickness.

These traits work in combination. High-density, coarse hair has entirely different needs than low-density, fine hair, even if both share the same curl pattern. Once you understand all three characteristics, you're ready to start building a hair care routine from the ground up that's genuinely tailored to your hair.