# Convert Acres to Square Miles

Enter the area in acres below to get the value converted to square miles.

**Results in Square Miles:**

## How to Convert Acres to Square Miles

To convert an acre measurement to a square mile measurement, divide the area by the conversion ratio. One square mile is equal to 640 acres, so use this simple formula to convert:

The area in square miles is equal to the acres divided by 640.

**For example,**here's how to convert 500 acres to square miles using the formula above.

Acres and square miles are both units used to measure area. Keep reading to learn more about each unit of measure.

## Acres

One acre is defined as the area equal to a space that is one chain (66 ft) by one furlong (660 ft), or 10 square chains.^{[1]} That's equal to 43,560 square feet for those unfamiliar with those units of measure.

The acre is a US customary and imperial unit of area. Acres can be abbreviated as *ac*, for example 1 acre can be written as 1 ac.

Try our acreage calculator to find the area of a plot of land in acres by locating the boundaries on a map.

## Square Miles

One square mile is equal to the area of a square with sides that are 1 mile long. One square mile is roughly equal to 2.59 square kilometers.

The square mile is a US customary and imperial unit of area. Square miles can be abbreviated as *sq mi*, and are also sometimes abbreviated as *mi²*. For example, 1 square mile can be written as 1 sq mi or 1 mi².

## Acre to Square Mile Conversion Table

Acres | Square Miles |
---|---|

1 ac | 0.001563 sq mi |

2 ac | 0.003125 sq mi |

3 ac | 0.004688 sq mi |

4 ac | 0.00625 sq mi |

5 ac | 0.007813 sq mi |

6 ac | 0.009375 sq mi |

7 ac | 0.010938 sq mi |

8 ac | 0.0125 sq mi |

9 ac | 0.014063 sq mi |

10 ac | 0.015625 sq mi |

20 ac | 0.03125 sq mi |

30 ac | 0.046875 sq mi |

40 ac | 0.0625 sq mi |

50 ac | 0.078125 sq mi |

60 ac | 0.09375 sq mi |

70 ac | 0.109375 sq mi |

80 ac | 0.125 sq mi |

90 ac | 0.140625 sq mi |

100 ac | 0.15625 sq mi |

200 ac | 0.3125 sq mi |

300 ac | 0.46875 sq mi |

400 ac | 0.625 sq mi |

500 ac | 0.78125 sq mi |

600 ac | 0.9375 sq mi |

700 ac | 1.0938 sq mi |

800 ac | 1.25 sq mi |

900 ac | 1.4063 sq mi |

1,000 ac | 1.5625 sq mi |

## References

- National Institute of Standards and Technology, Handbook 44 - 2014 Edition, https://www.nist.gov/sites/default/files/documents/2017/05/09/appc-14-hb44-final.pdf