Greetings,,,
3 9/16" in length. Just over 1 1/8" width. Almost 3/4" in height with components installed, including the solder joints on the bottom, don't forget.
You might have the standard slight variations, so if you're really trying to get close I would leave a little leeway. You also have to add the cable connections to this, to take into account. I'd get an actual board to check for yourself. PVC pipe is more forgiving, and is what I'm using.
Keith