How to Classify Your Hair with the Fia System

 The Fia info was copied from this site.  The info in purple was added by me.

Fia's Hairtyping System

FIRST CLASSIFIER:

The straight ones
1a - stick straight
1b - straight but with a slight body wave, just enough to add some volume, doesn't look wavy
1c - straight with body wave and one or two visible S-waves (e.g. nape of neck or temples)

The wavy ones
2a - loose, stretched out S-waves throughout the hair Beachy waves, Rock star waves
2b - shorter, more distinct S-waves (similar to waves from braiding damp hair) Princess hair.
2c - distinct S-waves and the odd spiral curl forming here and there Mix of waves, curls, and some pieces that have mixes of S and C shapes.  On naturallycurly.com it is often called "wurly" hair.   


The curly ones
3a - big, loose spiral curls Like a telephone cord (anyone else old enough to know what that is)
3b - bouncy ringlets Ringlets the size of a pinky finger.
3c - tight corkscrews Ringlets the size of a pencil or straw

The really curly ones Common among African Americans.
4a - tightly coiled S-curls
4b - tightly coiled hair bending in sharp angles (Z-pattern)

SECOND CLASSIFIER
What (most of) your individual strands look like

F - FineThin strands that sometimes are almost translucent when held up to the light. Shed strands can be hard to see even against a contrasting background. Similar to hair found on many people of Scandinavian descent.

You can also try rolling a strand between your thumb and index finger. Fine hair is difficult to feel or itfeels like an ultra-fine strand of silk

M - MediumStrands are neither fine nor coarse. Similar to hair found on many Caucasians.

You can also try rolling a strand between your thumb and index finger. Medium hair feels like a cotton thread. You can feel it, but it isn't stiff or rough. It is neither fine or coarse.

C - Coarse
Thick strands that where shed strands usually are easily identified against most backgrounds. Similar to hair found on many people of Asian or native American descent.

You can also try rolling a strand between your thumb and index finger. Coarse hair feels hard and wiry. As you roll it back and forth, you may actually hear it.

THIRD CLASSIFIER
Your overall volume of hair

Put your hair in a ponytail with as much hair as possible in it. Don't bother with the way it looks - the goal is to have most/all of your hair in there. If it means it sits smack dab on top of your head, put it there.

Measure the circumference of the ponytail. If you have bangs and/or you can't get all of your hair in there adjust according to how much of your hair you have measured.

To measure the circumference - take a piece of string, or a soft tape measure (the kind used by dressmakers). Wrap the string or tape measure around your ponytail - just below the elastic you have in to hold the ponytail together. Read the corresponding number from the tape measure, or hold the string at the length you've measured and use a ruler to determine how much it is. The number given is the circumference of your ponytail.

i - thin (less than 2 inches/5 centimeters)
ii - normal (between 2-4 inches or 5-10 centimeters)
iii - thick (more than 4 inches/10 centimeters)

Naturally Curly link with pictures of curl patterns.

Your curl pattern (or lack of curl pattern) may not fit neatly into one category.  It is common to see a mix of curl patterns on one head.  Some hair just simply doesn't fit any description.  
Figuring out hair texture can be tricky as well.  Your hair stylist should be able to tell you what your texture is.  If you compare hair with friends, this should help you to figure out your texture.  Livecurlylivefree.com has a service where you can send in your hair and they will tell you elasticity, porosity, and texture. 

My hair is 2bFi.  On a good day I'm 2cFi.

What does all of this mean? The link explains it.