Chris a particular size trowel that goes with a particular size tile is a misnomer and really isn't a practical approach to selecting a proper trowel for a given job.
Most all ceramic tiles around 12-16 inches square will be fine using a 1/4 X 3/8" trowel.
A better method of selecting a proper trowel is to know the condition and make up of the substrate and to know the construction of the backside of the tile.
Most thinsets do have a chart on the bag but there is little truth to what is printed there when it comes to real world practicalities in a lot of cases.
