How to Convert Linear Yards to Square Feet

There is some variability in how prepreg material is measured in the US. Generally woven materials, referred to as broadgoods, are measured in linear yards (LY) while some measure composite material by the square foot (SF). To make matters more confusing unidirectional prepreg is measured by the pound.

Sometimes, customers ask how many square feet a given prepreg order will be. Here’s a useful the quick 4 step process to convert linear yards (LY) to square feet (SF).

Here’s how to convert:

  1. Determine the width of the fabric. Most fabrics are 38”, 50”. (If the width is 50” then 1 LY would be 50 by 36 inches.)
  2. Divide the width by 12 (i.e. 12 inches in a foot)

In this case it would be 50/12 = 4.166

  1. Multiply your result by 3. This will give you the square footage of 1 linear yard:

4.166 x 3 = 12.5 (This material has 12.5 SF per 1 LY)

  1. So let’s say you ordered 60LY of material. You would then multiply the 60LY by 12.5 to find the SF. In this case your 60LY roll of material would be 750 SF.

Quick Conversions:

Know your width of your fabric and the LY?

Here are some quick conversions for 100LY combinations:

50” width, 100LY = 1250 SF

60” width, 100LY = 1500 SF

38” width, 100LY = 950 SF

Need 1,000 SF of prepreg material?


80LY of 50” material

~70LY of 60” material

~105LY of 38” material