At Casual Football Shirts I sell a lot of mystery shirts. These can be shirts from the 1990s through to the current day, depending on which product you order.
To sort out this issue I've come up with the Casual Football Shirts true sizing guide! As a side note, if the shirt does not fit you have 14 days to return it for an exchange - no problem at all.
True Size Guide
The guide works using the measurements from a modern Adidas standard replica shirt. This is the standard fit and not an authentic or player spec sizing. We use the below table as a guide for the pit to pit sizing to size up our mystery shirts. If you do not have a modern Adidas shirt, measure the arm pit to arm pit of a football shirt that fits you and use that as a guide for what size you need to order.
- Small - 18 inches
- Medium - 20 inches
- Large - 21 1/2