Your blocks at the point you have pictures need to measure 12 1/2 inch square. This gives you the 1/4 inch needed on each side to sew the seams putting multiple blocks together.
All blocks prior to sewing into a quilt are 1/2 inch bigger all way around...... hence 12 1/2 inch UNFINISHED and 12 FINISHED is used.
Great blocks by the way!!!