Never use the rip fence as a stop when crosscutting on your table saw – that’s a perfect recipe for kickback.
Instead, clamp onto the rip fence a piece of scrap to use as a stop block for the width of cut, as shown below.
Note that this setup is for illustration only – the blade is not raised high enough for a through cut.
Be sure to place the stop block far enough back that the stock you are cutting will not be in contact with the blade at the same time it is in contact with the stop block. Also keep the clamp out of the path of the stock.
The stop block also will allow for consistent length of cuts.