The measurements given for our chainmail are taken when the chainmail is fully expanded but you would never wear chainmail tight, you must allow sufficient excess for movement. When taking your measurements to assess the size required you must be wearing any clothing that you will normally wear beneath your chainmail be it a tunic or gambeson.
As a rule of thumb the chainmail should be at least six inches (15cm) more than you measure over your under padding, also remember that if your stomach measurement is greater than your chest measurement then use the large of the two measures. If you are border line then always air on the larger size as chainmail will shrink to fit you and will just be a bit longer the more it compresses.
Measured when the chainmail is stretched side to side.
This is measured with the chainmail stretched vertically and is measured from the shoulder
This is measured from the arm pit.