If you take the chest size & double it, that’s how many inches the jacket will fit around you. The other measurements will stay the same. So a Small will be 40 inches around your chest area.
Small
• Body Length: 26.25”
• Chest Width: 20”
• Sleeve Length: 27”
Medium
• Body Length: 26.75"
• Chest Width: 20.75
• Sleeve Length: 27.5"
Large
• Body Length: 27.25"
• Chest Width: 21.5"
• Sleeve Length: 28"