Fabric Math

I totally lied to my Algebra teacher when I said I would never use math in the real world.  If only I could have stayed away from quilting, then I could have shown him!  OK, fabric math, not very hard and essential!  Let's use the square as our example.  You have graphed your pattern and chosen to use 2 inch finished squares.  This means when your quilt is all put together your squares will be 2 inches.  That means you need to cut out 2 1/2 inch squares.  For today's example we will use 560 red squares and 430 white squares.  Let's assume that the width of the fabric will be 36 inches, yes I know its usually wider than that, but we are not interested in accuracy, we err on the side of caution.  The very minute you walk out of the fabric store, even if you turn around and walk back in, they run out of the color you just bought, it is a different dye lot, or they stopped making it altogether.  The upshot is you will never, NEVER find that color again, so plan accordingly.  Determine how many squares you can get in 1 yard of fabric.  Using 36 inches as our width, divide 36 by 2.5, the answer is 14.4 so round down and use 14 squares per 36 inches.  Now knowing how many squares fit across 1 yard the answer is the same for legnth.  14 squares.  Multiply 14 times 14 = 196.  This is how many squares are in  1 yard of fabric.  So we need 560  red squares.  In 2 yards of fabric we can get 392 squares, in 3 yards of fabric we can get 588 squares.  So I would get 3 yards of the red fabric.  Now in the white we only need 430 squares.  2 yards of fabric yield 392 squares plus 98 (which is half of  196) = 490, so I would buy 2 and 1/2 yards of white.  I know we will end of with extra material, but that is ok, it will give you fabric in your stash for that scrappy quilt!  Remember, these calculations are for your squares only.  If you want the same colors for binding, backing and borders factor these into your calculations before going to the store.

Quilt something beautiful today!