I find what works for me is to cut three strips of fabric two inches wide by five inches long.
Sew them together.
Press.
If my square is five inches by five inches, I'm doing good.
If it is less than five inches wide, the seam allowances are too deep/wide.
If more than five inches wide, make the seam allowances narrower.
Depending on how one places one ruler, etc., "your" two inch strip may be a tiny bit narrower or wider than "my" two inch wide strip.
So - this little sample/test can really save one a lot of aggravation.
A "scant" quarter inch is such an annoying instruction to me.
In my mind it is somewhere between 3/16 of an inch and 15/64 of an inch.
1/4 = 2/8 = 4/16 = 8/32 = 16/64