They measure 6 inches point to opposite point but flat edge to opposite flat edge they measure a little more than 5 1/8 but not quite 5 1/4. It would not make it easy to cut a few more hexagons to match the size from my own fabric with a hexagon ruler.
Of course, I could use the template that comes in the pack to cut more hexagons. I would do it by marking the fabric around the template and cutting on the lines using a straight ruler and my rotary cutter. The template is ordinary template plastic and I would not want to shave it with my rotary cutter. This photo shows the template on the hexagon from the pack, it is sized perfectly and the patches are all cut exactly.
What I want is to cut triangles to sew to 2 opposite edges and therein is another problem. The size triangle to cut is a size that also falls between the lines. If I make it a little bit larger and trim, it fits, but I lose the dog ears that help me line up the points.
This photo shows all the hexagons up on my wall but not in the order that I will put them together.
I am cutting a few more from my own fabric to replace some of the very light prints and I have worked out the size triangles I need.
This is getting to be more fussing around that I want to do if I am buying precuts.
If I were going to only sew the hexagons from the pack together with each other or another Honeycomb pack, there would be no problem. I could also use my hexagon ruler to cut each hexagon down to the next uniform size on the ruler (4 1/2 inches), so I might buy a Honeycomb pack again for the variety. I think that a hexagon ruler and triangle ruler or maybe the "Hex and More" ruler are probably the way I would go and either buy a fat quarter pack or a Dessert roll for the variety. Maybe after I put this all together I will decide that I was expecting a problem where none existed.