My chest measures at 37” and waist 27”. 5’10” and 117 lb and have rather long arms and wide shoulder.My jacket pictured above is in 36R. Cut is slim drop 7. And actual measurements adds about 4 inches. Armholes are high and sleeves are really slim . Tag 36 Has 40 inch chest. length is good(for DB)- 29" . But For me the sleeves are a bit too short. I need abut ¾ of an inch.I would say go for 40R.