17.25-17.5" if you had a real tape man at a show do it probably. David P Willoughby, who taped a lot of strongmen, Weightlifters, and bodybuilders taped necks a bit higher than you, and he had them stare straight across at something so that you didn't get head movement. He also used a steel pi tape, but that might be too expensive for normal folks.
Some numbers taken over the years -
Kaz-
neck-22"
biceps-21.4
forearm-16.6
wrist-8.6
chest-58.5
waist-42.2
thigh-31.5
calf-20.4
height-74
weight-320
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Patera
neck-22"
biceps-21.7
forearms-16.8
wrist-9.5
chest-58
waist-45
thigh-34
calf-21.5
height-73.5
weight-337
-------
Reinhouldt
neck-20"
biceps-21.8
forearm-17
wrist-9.4
chest-59.5
waist-46
thigh-31.5
calf-19
height-75
weight-345
-------
Whilhelm
Neck-21.5"
biceps-19.8
forearms-15.8
wrist-8.6
chest-57.5
waist-44
thigh-32.2
calf-18
height-75.5
weight-330
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