How many times smaller is the volume of a cylinder if the diameter is multiplied by 1/2

Calculating the volume of a cylinder the radius is squared,

If the radius was 8 when 8 is squared you get 64

If the radius is multiplied by 1/2 the radius would become 4, 4 squared is 16

16 / 64 = 1/4

The volume would be 1/4 the original volume, so it would be 4 times smaller.