This is such a cute little pattern, and a clever idea for both coaster and cozy. Next time I will do the i-cord bind-off a little more snugly for a more perfect fit.
gauge
US 6: 5 sts and 6 rows to 1”
US 3: 6 sts and 8 rows to 1”
mug circumference: 11.5” at rim/ 10.75” middle
mug base diameter: 2.5”
mug height: 6.25”