This document discusses how to calculate the grams per square meter (GSM) of a fabric based on its construction details. It provides the formulas to calculate the warp and weft yarn weights in grams using the ends per inch, picks per inch, warp/weft counts, and fabric width. An example calculation is shown for a fabric with 92 ends per inch and 104 picks per inch using 80 count warp and weft yarns. The GSM is calculated by adding the warp and weft yarn weights, which in this example is 59.28 GSM.

1. Fabric Weight Calculation in
GSM (Woven Fabric)
From Fabric Construction
Taukir Kabir Tusar
B.Sc. in Textile Engineering (BUTex)
Trainee – QA and Technical
Asmara International Limited

2. GSM calculation of fabric
Fabric is the basic raw material to produce any particular garments . Before going to bulk production , it
is quite essential to know and test the GSM of the supplied fabric by the supplier. This GSM can directly
be got through GSM cutter .
But the GSM can be theoretically evaluated via some calculations . We will discuss here that process.
What is GSM?
Fabric GSM means the weight of fabric in grams in per square meter area. So the higher the GSM , the
higher bulkier will be the fabric and vice versa , even they can be of same construction
Fabric Costruction
Fabric Construction is a term in which some fabric detailing are available such as EPI (Ends per inch –
warp) , PPI (Picks per inch – weft) , Warp count , Weft count and fabric width (in inches) . The formula
can be either of belows –
EPI x PPI EPI x PPI
x Fabric Width Or x Fabric Width
Warp Count X Weft Count Warp Count x Weft Count

3. Some Examples :
124x64 92x104 92x88
X48’’ = Poplin Fabric . x63 =Voile Fabric . x 54 = Cambric Fabric
40x40 80x80 60x60
All are cotton fabrics here
Calculation of GSM :
We wil calculate GSM for below one here –
Warp weight calculation :
Here , EPI = 92
So total number of ends = 92x39.37 (as we have to go to meter cause EPI is in inches
but GSM is in meter unit and 1 meter=39.37 inches )
= 3622.04
Length of each 1 meter yarn allowing the crimp % = 1m + 1m x 3% ( Let, warp crimp = 3%)
= 1m + 1m x 0.03
= 1m + 0.03 m
= 1.03 m
(this is necessary to find out 1 meter yarn length because when we take 1 meter in both warp and weft ,
it’s covered area will be 1mx1m =1m2
which is identical to GSM unit that is – Grmas per Square Meter)
So . total length of warp yarn = 3622.04x1.03 = 3730.71 m
Lx w
Now ,Warp Yarn Count , Newa
=
Wxl
( Here , L = Length found , w=1 lb = 453.6 gm , W= Weight
found/needed , l = 840x0.9144 meter)
[ As from the above formula , 453.6 gm means 1lb and 0 .9144 meter means 1 yd which came from the
definition of Ne where weight unit is fixed to 1lb and length unit to 840 yds as a constant in the formula]
# The number of hanks required of each having 840yds (1 hank) of yarn that can make 1 lb weight is
called the count (Ne) of that yarn
Lx w
Again, Warp Yarn Count , Newa
=
Wxl

4. 3730.71x453.6
=
Wx840x0.9144
1692250.06
W =
80x840x0.9144
= 27.54 gm
Weft weight calculation :
Here , PPI = 104
So total number of ends = 104x39.37 = 4094.48
Length of each 1 meter yarn allowing the crimp % = 1m + 1m x 5% ( Let, warp crimp = 5%)
= 1m + 1m x 0.05
= 1m + 0.05 m
= 1.05 m
So . total length of weft yarn = 4094.48x1.05 = 4299.21 m
Lx w
Now ,Weft Yarn Count , Newe
=
Wxl
4299.21 x453.6
=
Wx840x0.9144
1950121.66
W =
80x840x0.9144
= 31.74 gm
So the GSM of the fabric will be = 27.54 + 31.74 = 59.28
Here is a screenshot of a GSM calculator giving the same input and the result is correct !

5. Link to download the excel file :
http://www.mediafire.com/file/yaqah17i47iolhd/Fabric_Weight_Calculator_from_Construction_%28
_in_GSM_%26_oz-yd%5E2%29.xlsx