Bio

A bio is the smallest of the three units of length used by the MatoranMatoranThe most abundant species in the Matoran Universe, chosen by Mata Nui to inhabit and maintain his cosmic body. and other species of the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control.. One bio equals 4.5 feet, or 1.37 metres, in surface-world terms. The larger units are built from it: one thousand bio make a kioKioThe middle unit of the three-tier Matoran measurement system, equal to one thousand bio and roughly 0.85 miles, used to measure cities, islands, and the reach of some of the most dangerous powers in the universe., and one thousand kio make a mioMioThe top of the three-tier Matoran measurement system, equal to one thousand kio and roughly 850 miles, used for ocean crossings, inter-island distances, and the outer boundary of the inhabited universe.. (BIONICLE: Encyclopedia Updated)

The unit and its scale#

The guidebooks define the bio by its surface-world equivalent, 4.5 feet or 1.37 metres, and nothing more. They do not say how the unit came about, and they do not tie it to the height of any particular being. (BIONICLE: Encyclopedia Updated)

The one body measurement the books give is for the ToaToa (2001)Biomechanical heroes bonded to elemental powers and masks. Not born, but chosen and transformed.: all Toa, the BIONICLE: Encyclopedia Updated says, are roughly 1.6 bio tall, a little over 7 feet or about 2.2 metres. (BIONICLE: Encyclopedia Updated)

The ladder upward#

The bio is the bottom rung of a three-step system, with each step scaled by a factor of one thousand. One thousand bio make a single kioKioThe middle unit of the three-tier Matoran measurement system, equal to one thousand bio and roughly 0.85 miles, used to measure cities, islands, and the reach of some of the most dangerous powers in the universe., about 4,500 feet or 1.37 kilometres. One thousand kio make a single mioMioThe top of the three-tier Matoran measurement system, equal to one thousand kio and roughly 850 miles, used for ocean crossings, inter-island distances, and the outer boundary of the inhabited universe., about 850 miles or 1,370 kilometres. (BIONICLE: Encyclopedia Updated)

The even thousand-to-one scaling means any figure in bio can be divided by a thousand to read in kio, and by a million to read in mio, with no odd factors at any step. (BIONICLE: Encyclopedia Updated)

The bio in the story#

The bio suits short distances, where a kio would be far too coarse. (BIONICLE: Encyclopedia Updated; Reign of Shadows)

The clearest use in the story comes in Reign of ShadowsReign of ShadowsThe year Teridax ruled the Matoran Universe from inside Mata Nui's body, and the scattered resistance plots that ran against him until the Great Spirit returned from Bara Magna.. As the Toa MahriToa Inika and Toa MahriSix ordinary Matoran transformed by lightning from the Red Star into heroes who ultimately revived the Great Spirit itself. listened to a Skakdi rally, NuparuNuparuAn Onu-Matoran engineer from Metru Nui who built the Boxor and rose to become a Toa of Earth despite no warrior destiny. crouched with one hand on the soil and warned that something big was moving underground, maybe 20 bio from where they were. That works out at roughly 27 metres, close enough to demand a quick decision. (Reign of Shadows)

Why the bio matters#

The bio is the foundation of the Matoran system of length: the kio and the mio are simply a thousand and a million bio. (BIONICLE: Encyclopedia Updated)

For readers, the bio is mainly a conversion key. Knowing that a bio is 4.5 feet, and that Toa stand about 1.6 bio tall, lets figures in the books and serials be read in familiar terms, from Nuparu's 20 bio up to distances measured in kio and mio. (BIONICLE: Encyclopedia Updated; Reign of Shadows)