How to calculate Fabric consumption

Lets calculate the fabric consumption of a basic T-Shirt: 

 

 

Here,

1/2 chest =53 cm

Sleeve length (SL) = 18 cm

Center length (CL) = 69 cm

G.S.M = 145

Calculation: 

{(SL+CL+10) * (1/2 chest) * 2 * 12 * G.S.M} / (100 * 100 * 1000)

= {(18cm + 69cm + 10cm) * (53 cm) * 2 * 12 * 145} / 10000000

= 1.789068 Kg/Dz

Adding rib: We add 5% for regular T-shirt & 7% for kids T-shirt

= 1.789068 + 5%

= 1.8785214 Kg/Dz

Adding 13% Wastage:

= 1.8785214 + 13%

= 2.122729182 Kg/Dz

 So we need 2.122729182 Kg of fabric for making 12 pieces (Dz) of T-shirt.

Formula Analysis:

{(SL+CL+10) * (1/2 chest) * 2 * 12 * G.S.M} / (100 * 100 * 1000)

• Here 10cm is total sewing allowance. (2.5cm + 2.5cm at two sleeve. And 5cm at bottom) 
• We are multiplying 2 because we have back part & front part of the body. 
• We calculate the fabric consumption for 12 piece. So we are multiplying 12.
• First 100 is for making the length in miter. Because G.S.M is always in miter.
• And similarly 2nd 100 is for getting the width in miter.
• Finally 1000 is for getting the result in Kg. Because we have weight (G.S.M) in gm.  

If you have any question about this calculation please comment.

Calculate G.S.M of Woven fabric from its Construction:

G.S.M = (EPI/warp count + PPI/Weft count) x (100+crimp %) X 0.2327

Examples:

 Suppose,

Construction of a 100% cotton poplin fabric is 40s X 40s / 133 X 72 (here, EPI=133 & PPI=72) and warps and weft crimp is 6%.

Then G.S.M of this fabric will be …..

G.S.M = (133/40 + 72/40) X (100+6%) X 0.2327

=> G.S.M =126.414

N.B Here 0.2327 is multiplying factor for G.S.M

But someone use this formula with different multiplying factors like …….

G.S.M= ((EPI/warp count X 1.1) + (PPI/weft count x 1.04)) x 23.5
Where 1.1 and 1.04 are warp and weft crimp factors respectively.