Creme Brulee starting wt - 27 gr, end 17 gr
Begonia starting wt 26 gr, end 18 gr
I didn’t lhave any DK wt cotton to do the test, so used KP Dishie which knits up a bit smaller than most worsted wt cottons for me.
My coaster measured 5-1/4” wide and 5-1/2” tall, unblocked

I have some sport wt Hempster yarn that would make a smaller coaster - maybe I’ll try using it to see how it works.

I used crochet chain cast on and regular bind off.