# Turn (angle)

A **turn** is a unit of plane angle measurement equal to *2π* radians, 360 degrees or 400 gradians.
Subdivisions of a turn include half-turns, quarter-turns, centiturns, milliturns, etc.

Turn | |
---|---|

Unit of | Plane angle |

Symbol | tr or pla |

Conversions | |

1 tr in ... | ... is equal to ... |

radians | 2π rad ≈ 6.283185307... rad |

milliradians | 2000π mrad ≈ 6283.185307... mrad |

degrees | 360° |

gradians | 400^{g} |

The closely related terms *cycle* and *revolution* are not equivalent to a turn, since these are not units of angle.