Select the rope diameter:
5/16" (.3125)   3/8"  (.375)      7/16" (.4375)     
1/2"  (.5)      9/16" (.5625)     5/8"  (.625)     
3/4"  (.75)     7/8"  (.875)      1"     
9/8"  (1.125)   5/4"  (1.25)      Unknown