Kio

A kio was the middle unit of distance in the three-tier measurement system used across the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control.. It was defined as one thousand bioBioThe smallest of the three Matoran units of length, equal to 4.5 feet or 1.37 metres, from which the kio and the mio are built. and converted to roughly 0.85 miles or 1.37 kilometres in surface-world terms. Above it sat the 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., defined as one thousand kio. The kio shows up wherever a number was needed that was too big for bio and too small for mio: city and island dimensions, the reach of senses, and the radius of effect for some dangerous powers and artefacts. (BIONICLE: Encyclopedia Updated)

The three-tier measurement system#

The Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control. used its own system for measuring length, made up of three units scaled on a thousand-to-one ratio at each step. The base unit was the bioBioThe smallest of the three Matoran units of length, equal to 4.5 feet or 1.37 metres, from which the kio and the mio are built., defined as 4.5 feet or 1.37 metres. As a reference, a ToaToa (2001)Biomechanical heroes bonded to elemental powers and masks. Not born, but chosen and transformed. stands roughly 1.6 bio tall. The middle unit was the kio, defined as one thousand bio. The largest unit was the 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., defined as one thousand kio. (BIONICLE: Encyclopedia Updated)

The pattern is easy to read in the story. The bio fits the scale of a single being; the kio fits the scale of cities, islands and the ranges of powers; the mio fits the larger distances beyond that. (BIONICLE: Encyclopedia Updated)

Conversions and equivalents#

A kio is equal to 4,500 feet, 0.85 miles, or about 1.37 kilometres. By the same scaling, one kio is exactly 1,000 bio (each bio at 1.37 metres), and 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. (850 miles or 1,370 kilometres). That gives a clean conversion ladder: any figure in bio can be divided by a thousand to read in kio, and any figure in kio multiplied by a thousand to read in bio, with no odd factors at any step. (BIONICLE: Encyclopedia Updated)

The clean ratios made the kio the natural unit for any measurement that would turn into an awkward four- or five-digit number in bio, and it is the one that crops up most often when characters talk about distance. (BIONICLE: Encyclopedia Updated; Brothers In Arms)

Cities and islands measured in kio#

The kio was the standard unit for the geography of the major settled regions. The city of Metru NuiMetru NuiThe city beneath Mata Nui functions as the Great Spirit's brain, housing the Matoran whose labor keeps the god alive. measured 47.6 kio in length and 24 kio in width, roughly 40.5 by 20.4 miles or 65.2 by 32.9 kilometres in surface terms. (BIONICLE: Encyclopedia Updated)

The island of Mata NuiMata Nui (Location)An island created by accident on the Great Spirit's face, home to the Matoran for a thousand years., where the Matoran lived after the Great CataclysmThe Great CataclysmThe day Makuta Teridax put the Great Spirit to sleep, the Great Spirit Robot fell from the sky, Metru Nui flooded, and Voya Nui tore loose from the Southern Continent., measured 357 by 178 kio, roughly 303 by 151 miles or 489 by 244 kilometres, making Metru Nui about a seventh of its length. (BIONICLE: Encyclopedia; BIONICLE: Encyclopedia Updated)

Ranges of effect and the dangerous edge cases#

The kio appears in the story as the radius of effect for unusual powers and artefacts. The Nui StoneNui StoneA red artifact that hunts Toa and drains their power within 3000 kio, sought by Tuyet in ancient Metru Nui to gain strength against enemies only she could see., a red crystal about the size of a Toa's fist, slowly absorbs energy from any ToaToa (2001)Biomechanical heroes bonded to elemental powers and masks. Not born, but chosen and transformed. within a 3,000 kio radius, so gradually that the victims don't notice until it's too late, and another Toa can then tap the stone for that power. The figure works out to roughly 2,550 miles. (The Many Deaths of Toa Tuyet; Reign of Shadows)

At a smaller scale, De-MatoranDe-MatoranMatoran with Sonics powers who valued silence so deeply that they didn't welcome Toa and the conflict they bring., the Matoran of sonics, have hearing so sharp that the Toa Jerbraz said they could follow a conversation from a kio away. (Brothers In Arms)

The same scaling appears in the aftermath of The Shadowed OneThe Shadowed OneThe Shadowed One is the leader of the Dark Hunters, a black, yellow, and silver figure based on Spherus Magna. Armed with a staff and a Rhotuka, the Shadowed One directs the organization.'s disappearance on XiaXiaA hostile island southeast of Metru Nui, home to the Vortixx and their brutal mercenary culture. 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.. Every VortixxVortixxThe amoral weapons dealers of Xia who sold to anyone willing to pay. within a kio of his chamber had been pulverised into fragments, with no sign of what had done it, and the investigators were left with a kio-wide zone to puzzle over. (Reign of Shadows)

Why the kio became universal#

The kio's place as the most often quoted of the three units makes sense. It matches the scale at which the Matoran UniverseMatoran UniverseA civilization of biomechanical beings living inside a colossal robot, destroyed when Teridax seized control. stories usually work: the size of a city like Metru NuiMetru NuiThe city beneath Mata Nui functions as the Great Spirit's brain, housing the Matoran whose labor keeps the god alive., the width of an island, the reach of a sense or a power. Bio would give unwieldy numbers for those distances and mio would give tiny fractions. (BIONICLE: Encyclopedia Updated; The Many Deaths of Toa Tuyet)

The clean thousand-to-one ratio with both bioBioThe smallest of the three Matoran units of length, equal to 4.5 feet or 1.37 metres, from which the kio and the mio are built. and 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. also means there are no awkward conversions anywhere on the ladder, which is a big part of why the unit is so easy to use. (BIONICLE: Encyclopedia Updated)