I’m sure that some mathematician has worked this out before but I worked out the following ratio system for assessing the appropriate size for a watch on a wrist.



Its pretty simple



1/ Convert wrist size into mm



2/ Divide total wrist size in mm by the size of the watch



eg A 7 inch watch and a 38 mm watch = 178mm divided by 38mm= Ratio of 4.7



This brings me to the controversial part. What is an acceptable ratio? I think using this formula, that an acceptable ratio falls between 4.0 and 5.0. Anything below 4.0 is too big and anything above 5 is too small.



Here is an example using a 44mm watch which should be too big for some with smaller wrists



6.5 inch ( 165 mm) Ratio=3.75 Too big

7.0 inch (178mm) Ratio=4.0 Just ok- acceptable

8.0 inch (203 mm) Ratio=4.6 Great fit



This brings me to interesting observation that wearing a 39 mm watch on a 7 inch wrist has a a very similar Ratio as wearing a 44mm watch on an 8 inch wrist. That is, a ratio of about 4.6.



For reference, here are the conversions for wrist size

6 inch = 152.5 mm

6.5inch = 165mm

7inch = 178mm

7.5inch= 190.5mm

8.0inch = 203mm

8.5 inch = 216mm



I realize I am opening myself up to ridicule for being too analytical but I think it’s a pretty useful way to work out a rough guide and obviously does not take into account lug shape etc. What do you think? Has someone worked this out before? Have I got too much time on my hands? Can this concept be improved on?



Cam