Is there any formula to find out woven garment consumption without CAD?

Fabric marker for consumption calculation


This question was asked by an OCS reader. And the short answer to this question is 'YES', there is a formula to find out woven fabric consumption. 
 
In this post, I will show you how to establish fabric consumption theoretically (using mathematical formulas).

If you are working in the garment manufacturing sector, you may already know that the fabric consumption of any garment is calculated by making patterns and garment markers. The CAD system also uses garment patterns to estimate fabric consumption. 

Factories and individuals who don’t have CAD system, they can find out fabric consumption by making manual markers. So, you can find out fabric consumption by making the manual patterns of the garment design and making sample markers from those patterns.

But I see you are looking for a formula to calculate woven garment consumption.

From the marker, you will get the length of the fabric required for making one piece of garment. The length of the fabric in meters/yards will be the consumption for the garment.

While making the manual marker for fabric consumption, take care of fabric width as well. You need to utilize fabric width as maximum as possible. Lay patterns for the second garment if you see there is a balance fabric width-wise. Later calculate per piece fabric consumption. Instead of making a 1-way marker, make a 3-4 way marker (including mix sizes), this would give an average fabric consumption for the given style.

If you like to calculate fabric consumption based on the measurement and theoretical calculation, you can do that as well. But remember, the calculated consumption may differ from the actual consumption (that is made based on a marker).

I have published one online calculator for calculating fabric consumption for a woven shirt based on the shirt measurements. Check that out for a ready reference.

Find out fabric consumption using math

You need to follow the below steps to calculate fabric consumption. 

1. Take your sample garment (Woven garment) and identify all components of the sample.

2. Make a list of parts on paper to make sure you are not missing any garment parts in the calculation process.

3. Measure the length of width/height of all the garment components. Take measurements in the same Unit of measure (either in centimeters or in inches). Measure the seam allowances in width-wise and length-wise and folding width where applicable.

4. Check the number of layers and parts needed for each garment component

5. Calculate the rectangular areas of all garment components by following this formula.

Area of each part = (Part's length x part's width x number of parts) 

For example, in a formal shirt,  you need 4 plies for the sleeve cuff, and for a collar, you need to cut two layers.  Let's say,
Cuff length= 25 cm + seam allowance 2 cm = 27 cm
Cuff width = 6 cm + seam allowance 2 cm = 8 cm
Area of the single Cuff panel=27 x 8 Sq. cms
Area of the all cuff panels for a shirt = (27 x 8 x 4) square cm = 864 sq. cms = 0.0864 Sq. meters

6. Calculate total area by summing up all component’s areas. Let's consider the calculated area is in square meters.

For example, let's say, you got the total calculated area of all woven garment components = 1.68 sq. meters

7. Measure the fabric width in meters (if you have fabric width in inches, convert it in meters by dividing the width value by 39.37). Let's say fabric width 1.2 meters

8. The calculated area includes only garment parts. In production cutting, there will be end bits, edge loss, side loss, and fabric defects that need to be considered in estimated fabric consumption. 
For that, you also need to include an allowance for fabric waste. The fabric wastage percentage would widely very be depending on the garment design, cutting method, and fabric width. Now it is very difficult to say how much fabric waste allowances should be considered. 
For example, Let's consider a 10% fabric waste allowance.

Now measure the fabric length that you need to make one garment.

Fabric consumption in length
= (Total area of garment patterns/Fabric width) x Wastage percentage
= (1.68/1.2) x 10%
= (1.68/1.2)x 1.10
= 1.54 meters


Related post: How Much Fabric Do I Need for Making Kurtis for Women?

If you use/know any other ways to estimate woven fabric consumption, please share the same with us.