Woolen yarn count is not as straightforward as the worsted count system as there are 4 different woolen yarn count systems in use and each system uses a different fixed weight as the standard.

Two of the woolen count systems are based on a cut length unit. They are the Galashiels and the Philadelphia. A Cut, according to Mabel Ross writing in her book “The Encyclopedia of Hand Spinning”, is: "...the number of cuts of singles yarn, each 300 yards long, which together weigh 24 ounces (i.e. 200 yards weigh one pound).

In the Galashiels system: 200 yards per 1 lb of fiber = 1’s.

In the Philadelphia system: 300 yards per 1 lb of fiber = 1’s. This is the most commonly used woolen count system.

The Yorkshire system is based on skeins: 256 yards per 1 lb of fiber = 1 Yorkshire skein, which is abbreviated as Y.sk.

The West of England system is based on hanks: 320 yards per 1 lb of fiber = 1’s.

To figure your Worsted Yarn Count:

Remember that if you are spinning a woolen yarn rather than a worsted yarn, you must use one of the fixed weight system woolen factors rather than the worsted factor.
Let’s work through figuring woolen count on the Philadelphia system, which has a fixed weight factor of 300:

Take the number of yards of yarn; let's say 450 yards
divide that by the weight of the yarn, say 8 ounces.
That’s 56.25 yards per ounce.
Multiply the 56.25 by 16 (1 lb). This comes to 900 yards per pound.
*Now take the 900 YPP times the number of plies in the yarn, let's say 2....
900x2 = 1800 yards.
Now divide the 1800 by the factor for the fixed weight system, which in this case is Philly woolen so the FWS factor is 300 and you have 1800 yards divided by 300 for a woolen count of: 6.
For singles, simply omit the step marked with the *. So in our example, the final step would be: 900 yards divided by the Philly woolen factor of 300 = 3. Philly woolen count of the singles is 3.

Here is a list of the FWS yardage numbers needed to figure count:

Worsted: 560
Woolen:
1. Philadelphia – 300
2. Galashiels – 200
3. Yorkshire – 256
4. West of England - 320

Next: Cotton, silk, and linen counts