. How do you rip a 2x4 exactly in half

Are you using a fence on your table saw? Remember when measuring that 2x4's are not 2" x 4" if surfaced, but generally 1½ inches thick and 3½ inches wide. Anyway, mark center point, lay on saw, flip over to make sure mark is centered from both sides of board. Set fence. Cut.

Measure 1 and 3/4 inch to the middle of your blade, cut a bout an inch into it then turn your board over and see where the cut goes. adjust as needed

Remember to allow a little bit on your measurement for the small bit of wood that will come off where the saw blade cuts. That may be throwing your measurements off a bit.

Thanks for the help but issue I think is getting the correct measurement so that it I get an two identical pieces and this is for 2x4 or 1x4 or 2x6 etc. I take in account kerf and try to get true measurement. The last thing I tried was to take a framing square and draw a 90 and then off of that line, I drew a 45 and then flipped the square over and drew another 45. I did several of these and drew a line where the lines met and cut on this line with the saw blade in the center against the fence. . This is a close as I have come to making two identical 2x2's out of a 2x4. Wondered if there was another option like this. I am using pallet wood and reclaimed wood and reclaimed 2x4s so dimensions are probably not going to be as accurate as I want.