Spinning count is a measure of fibre fineness and distribution developed by the English. It is defined as the number of hank

Hank

In the textile industry, a hank refers to a unit of yarn or twine that is in a coiled form. This is often the best form for use with hand looms, compared to the cone form needed for power looms. Hanks come in a fixed length depending on the type of material, so the term hank is sometimes used as a...

s of yarn that can be spun from a pound

Pound (mass)

The pound or pound-mass is a unit of mass used in the Imperial, United States customary and other systems of measurement...

 of wool. A hank of wool is 560 yard

Yard

A yard is a unit of length in several different systems including English units, Imperial units and United States customary units. It is equal to 3 feet or 36 inches...

s long (560 yd/lb = 1.129 km/kg). In theory a pound of 62s wool could produce 34720 yards of yarn.

As it is now a relative simple matter to measure the average fibre diameter and distribution, spinning count is being replaced with the specification of average fibre diameter in micrometers

Micrometre

A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...

 and fiber distribution in standard deviation

Standard deviation

Standard deviation is a widely used measure of variability or diversity used in statistics and probability theory. It shows how much variation or "dispersion" there is from the average...

s.