The atoll of Rangiroa consists of about 415 motus, islets and sandbars comprising a total land area of about 170 km². There are approximately one hundred narrow passages, called r'oa, in the fringing reef.
The atoll has a flattened elliptic shape, with 80 km in length and a width ranging from 5 to 32 km wide. The lagoon has a maximum depth of 35m and its surface is 1446 km². It is so large that it has its own horizon.
Only two islands, located on the northern end of the atoll, are permanently inhabited. As of 2007, the total population on the atoll of Rangiroa was 2,473 inhabitants. The main villages are Avatoru, Tiputa, Ohutu, Taeo'o, Fenuaroa, Otepipi and Tevaro.
Rangiroa is a major underwater diving destination because of its lagoon's clear blue water and exceptionally diverse marine fauna. The most popular diving sites are the Blue Lagoon, Avatoru pass, Tiputa pass and Les Sables Roses ("The Pink Sands").