When it comes to spinning wool, there are two major divisions of wool yarns under the Fixed Weight System (FWS): Woolen and Worsted. The count for these two types of yarn is figured differently and, in the case of woolen yarns, there are four different count methods in standard use today.

Let’s look at the Worsted Count System. This yarn count system arose out of the Bradford Count System which is a subjective system use to determine the degree of fineness of a fleece. The Bradford count system, as it was applied to spun yarn, came to be known as the Worsted Count System and is based on the maximum number of 560 yard skeins that can be spun from 1 pound of combed top spun worsted. When a fleece is graded with a Bradford Count of 56s (s = skeins), it means that a total of 56 skeins each 560 yards in length was the maximum number of skeins that could be spun from that pound of prepared fibers. A pound of 60s fibers would yield a maximum of 60 – 560 yard skeins while a pound 38s combed top would yield a maximum of only 38 – 560 yard skeins.

The Bradford Count System began with the sheep breeding industry and was used as the standard for the subjective evaluation of the fineness or coarseness of grease fleece and that the count is always given as a range rather than as a fixed number. For example, Corriedale has a Bradford range of 50s to 58s. One pound of combed Corriedale fibers from one sheep may yield a maximum of 50 skeins while another will give a maximum for 58 skeins.

Writing in his book The Wool Textile Industry in Great Britain, John Geraint states: "Originally these numbers (Bradford Count) referred directly to the thickness or count of yarn it was possible to spin from the wool, but over the last two hundred years this correlation has been lost and there is little or no connection between wool quality and worsted yarn count spun."

In other words, the Bradford Count of the fleece going into the yarn and the actual Worsted Count of the yarn are two different things. The Worsted Count does not change the Bradford Count. If you start with one pound of combed top that is 56s Bradford and spin it worsted to 3 – 560 yard skeins of singles yarn, the Worsted Count will be 3’s. The wool making up that yarn will still be 56s Bradford.

To figure your Worsted Yarn Count:

Take the number of yards of spun 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 worsted so the factor is 560 and you have 1800 yards divided by 560 for a worsted count of: 3.2.

To figure the count for a singles worsted, simply omit the step marked with the *. So in our example, the final step would be: 900 yards divided by the worsted factor of 560 = 1.6. The worsted count of the singles is 1.6.

Or: Number of yards divided by weight of yarn times 1 lb (16 oz or 454 grams) times the number of plies divided by 560 equals Worsted Count.