The most common gauge for a nose piercing is 18 gauge (1.0 mm) . However, some people choose to downsize their jewelry after the piercing heals to 20 gauge (0.81 mm) because of the variety of jewelry options available in the smaller size. Occasionally, people choose to go down as small as 22 gauge (0.76 mm), but professional piercers discourage using jewelry thats thinner than 22 gauge since these jewelry pieces can deform easily. Its important to note that a post thinner than 20 gauge is not recommended for most nose piercings.