Measuring from a shirt you own.
One of the most effective ways to know what size to order is to measure a good fitting shirt you own and compare this with the above table.

To measure your shirt place the shirt on a flat surface all button up and use the following graphics to get the measurements and compare with the above table.

Please keep in mind these tropical shirts are supposed to be loose and not fitted. Camp shirts are worn un-tucked and they can be a bit longer than a regular shirt.