how far is sha tin from tsim sha tsui, hong kong? cheapest way to travel between the two areas

The distance between these two areas is about 7.7 miles.
You can take MTR. From Tsim Sha Tsui to Sha Tin, take West Rail Line at East Tsim Sha Tsui Station, and get off at Hung Hom Station. Then transfer to East Rail Line to Sha Tin Station, Exit A4. It takes around 25 mins on the way. And the ticket fare is 8.6 HKD.
After arriving, walk to the destination directly.