Age 53 is the cutoff for wearing jeans, according to a study by British parcel delivery and return firm CollectPlus. Age 53 is the cutoff for wearing jeans, according to a study by British parcel delivery and return firm CollectPlus. The study looked into the jeans-wearing habits of Brits and how difficult it is to find the perfect pair, with some shoppers admitting to looking up to five days for the right fit, according to the Daily Mail.