Calculating number of Squares for a Quilt
I am trying to determine the number of charm packs I need to make a quilt for my bed; to do this, I need to determine the number of 5" squares needed. I found a guide to doing this, and this is the result I came up with. My question is: Does this make sense -is it correct? This is how I did the math:
The width of my mattress, which includes the 17: drop on the sides of the mattress):
71" /4.5" (allowing for seam take up)= 15.77=16 (rounded up)
The length of my mattress, which incudes the 17: drop:
109/4.5 (allowing for seam take up)=24.22=25 (rounded up)
So, 16 X 25 = 400 -5" squares
The charm pack I am buying has 40 5: squares, so I need 10 charm packs to cover my 71: X 109" (including drops) quilt.
Does this look right? Did I mention that I HATE math? Oh, well... Thanks for any advice you may offer!