Is there a size requirement for a 'ring' in space to achieve centrifugal force?

I'm curious, is there a required size for something like a habitable ring in space to achieve 1g of centrifugal force (or close to 1g)? For instance, if a spaceship of the near future was to be equipped with a rotating ring say thirty-meters in diameter, would that ring be large enough to achieve that kind of centrifugal force? If so, how fast would that ring need to spin? Would the small size require a faster rotation?