Here's the table that was used. This assumes a nice, thick, strong rope. You can work out the formula.

Hanging drop (assuming thick strong rope):

Weight                                 Drop

14 stone (196 lbs.)                   8 ft. 0 in.
13 1/2 stone (189 lbs.)                8 ft. 2 in.
13 stone (182 lbs.)                   8 ft. 4 in.
12 1/2 stone (175 lbs.)                8 ft. 6 in.
12 stone (168 lbs.)                   8 ft. 8 in.
11 1/2 stone (161 lbs.)                8 ft. 10 in.
11 stone (154 lbs.)                   9 ft. 0 in.
10 1/2 stone (147 lbs.)                9 ft. 2 in.
10 stone (140 lbs.)                   9 ft. 4 in.
9 1/2 stone (133 lbs.)                9 ft. 6 in.
9 stone (126 lbs.)                     9 ft. 8 in.
8 1/2 stone (119 lbs.)                9 ft. 10 in.
8 stone (112 lbs.)                     10 ft. 0 in

I guess if you weighed more than 196 lbs. they didn't hang you.

Aren't you glad to find this sort of thing out? You never know when you might need to know this stuff.