What is the standard kitchen island size?

Standard kitchen island dimensions:

36 inches wide x 24 inches deep x 36 inches high. This creates a workspace on the island side that accommodates most people standing at the counter, and allows at least 18 inches of leg room on the seating side.

39 inches wide x 36 inches deep x 36 inches high. This accommodates a wider range of heights and allows for a bit more leg room on the seating side.