i think the dimensions he gives are board lengths, because if u notice on the left side the board comes all the way to the front of the box. on the right side the side board meets the front board....do math....19.5-18.75=0.75" (board thickness).
its not, he just decided to label it where the pieces would individually be placed, however with the joints drawn as 45s its not easy to read.
what i dont get is where you said it was 25 x 25 x 19, yet it shows 19.5 deep on one side.
2 different boxes. Saywhat Im building your box for HT. Im building this one for SQL. Sorry bout the 45 degree angles. And Yes moe your right, it is 19.5 (that was a typeo on my part. Thanks everyone.