Problems and solutions of textile

A Practical Solution of Fabric GSM Calculation

A Practical Solution of Fabric GSM Calculation
Amit Kumar Das
Founder of "টেক্সটাইল ম্যানিয়া" Blog
Pabna Textile engineering college, Pabna, Bangladesh
Cell: 01770 456240


GSM means the weight of fabric per square meter. GSM is regarded as most influential properties for knitter goods. GSM is determined by using a simple type of machine called GSM cutter.
          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 means Wales per inch that means number of wales adjusted to each inch of fabric. For determining this at first we need to measure wales number for 10 inch. After this will divided it by 10. Because determining wales for one inch is so top.
Course per inch, with the help of counting glass and needle we will measure the number of course in fabric for 5 inch. then divided it by 5.

SL (Stitch Length): 

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


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

                                  N x L x 453.6
English count (Ne) = ----------------------
                                  wt x 36 x 840


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 (0.34x10)
= ----------------------------

= 64.26 (ANS)