**GSM:
**GSM means the weight of fabric per square meter. GSM is regarded as the most influential property for knitter goods. GSM is determined by using a simple type of machine called a GSM cutter. Here, we will know about the different fabric GSM calculation formulas.

………….Course per inch x stitch length x 39.37 x 39.37

GSM = ————————————————————————-

…………………………………1000 x 1000

Another alternative theory,

…………..WPI x CPI x SL (mm)

GSM = ————————————

…………………..Count (Ne)

**WPI: **

WPI means Wales per inch which means a number of wales adjusted to each inch of fabric. For determining this at first we need to measure wales’ number for 10 inches. After this will divide it by 10. Because determining wales for one inch is so top.

**CPI: **

Course per inch, with the help of counting glass and needle we will measure the number of course in fabric for 5 inches. then divided it by 5.

**SL (Stitch Length): **

Stitch length is called the distance between two adjacent needle lopes. Fabric’s weight and the dimension of fabric is highly dependent for its stitch length.

**Count: **

At first, the yarn needs to be untwisted. Then length and weight of those untwisted yarn should be detected with those data we can determine the actual count of the yarn.

**A Practical Solution of Fabric GSM Calculation**

……………………………….N x L x 453.6

English count (Ne) = ————————

……………………………….wt x 36 x 840

Where,

N = Yarn number

L = yarn length

wt = yarn’s weight

But there we have one more theoretical equation for count

…………………Ks x Tex

GSM = —————————–

…………Stitch length (mm)

Ks is a constant for respectable fabrics

Count theory for woven yarn,

……………………EPI PPI

GSM = ————————– + —————————— x 23.5

………….Warp count x 1.1 Weft count x 1.04

**Mathematical Example:**

Find out GSM from given datas. A fabric with 18 wales per inch and 21 courses per inch and stitch length 0.34cm with count 20 (Ne).

Then respective,

…………..WPI x CPI x SL (mm)

GSM = ————————————

………………….Count (Ne)

…..18 x 21 x (0.34×10)

= ——————————–

…………….20

= 64.26 (ANS)

Author of this Article:Amit Kumar DasFounder of "টেক্সটাইল ম্যানিয়া" Blog Pabna Textile engineering college, Pabna, Bangladesh Cell: 01770 456240 Email: [email protected]