How to Calculate a Fabric's Stretch Percentage

Knowing how to calculate a fabric's stretch percentage can be confusing if you are new to sewing. Well today I {Mel} will take out all the guesswork on how to Calculate a Fabric's Stretch Percentage for you.

Sewing patterns for stretch knits will often stipulate the fabric stretch percentage required to suit the pattern. It is important to have enough vertical and horizontal stretch in the fabric to ensure your finished garment fits well and is comfortable. 

So, in order to work out how to calculate a fabric's stretch percentage, gather the following items:

  • Test square of fabric (I like to use 10cm x 10cm)
  • Ruler
  • Basic maths skills, or a calculator


Step 1 - Place your ruler horizontally down on a flat surface.

Step 2 - Measure your fabric width (unstretched). Note down this measurement. 

Step 3 - Holding the edge of the fabric at zero on the ruler, stretch it out along the ruler as far as it will go. Note down this measurement.

Step 4 - Now let's do some basic maths. Stretched fabric measurement, as noted down in step 3) divided by (unstretched fabric width, as noted in step 2) minus 1 = stretch percentage.

For example, if you used a 10cm x 10cm square of fabric the equation will look a little like this:

15cm (stretched) ÷ 10cm (unstretched) - 1 = 0.50

Therefore your stretch percentage for this particular fabric is 50%. 

Repeat the above process to calculate the horizontal and vertical stretch percentage of the fabric, as both are equally important to take into account for garment construction. 

I highly suggest checking the stretch percentage required in any pattern and calculating the fabric you wish to use, as it only takes a few minutes and will save a lot of heart ache and tears. 

Have any questions or comments? Drop me a line on the Melco Fabrics Facebook Page. This is also where I share discount codes, tips, tricks and new fabric drops. 

Click here to shop the Melco Fabrics range of stretch fabrics.  

I hope you can now Calculate a Fabric's Stretch Percentage with ease!

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