### What is an Acre?

Ahead of explaining how to convert square miles to acres, let us first define what a mile and an acre is. The acre(ac) is the most commonly used unit for the measurement of large land areas and is used in both the imperial and US customary systems

### What is a Square Mile?

While a square mile(sq.mi) is a unit of area measurement equal to a square measuring one mile on each side. Square mile is also a standard unit to calculate population numbers in a specific area. So the population numbers are often described in per square mile terms.

### Formula to Convert Square Miles to Acres.

To convert sq. mi to acres, we need to know the conversion ratio which we get from how they relate to each other.

We are told that 1 sq. mi is equal to 640 acres.

Therefore, to convert sq.mi to acres, we multiply the sq. mi value by 640.

**Area in acres = Area in sq. mi x 640**

**Example 1:**

Convert 400 miĀ² to acres.

**= 400 x 640**

**= 256,000 acres.**

**Example 2**:

Suppose you have a piece of land whose length is 250miles. If both of its sides are equal, calculate the area of the land in acres.

We begin by finding the area of the land.

**Area = Length ^{2}**

**= 250 x 250**

**= 62,500 sq.mi.**

Then proceed to convert the area sq.mi to acres.

**= 62,500 x 640**

Therefore, the area of land in acres is 40,000,000.

### Square Miles to Acres Conversion Table.

Square Miles | Acres |

1 | 640 |

2 | 1,280 |

3 | 1,920 |

4 | 2,560 |

5 | 3,200 |

6 | 3,840 |

7 | 4,480 |

8 | 5,120 |

9 | 5,760 |

10 | 6,400 |

11 | 7,040 |

12 | 7,680 |

13 | 8,320 |

14 | 8,960 |

15 | 9,600 |

16 | 10,240 |

17 | 10,880 |

18 | 11,520 |

19 | 12,160 |

20 | 12,800 |