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Acres to Square Miles Converter

Convert acres to square miles and square miles to acres instantly. Bidirectional area converter with formula and common values.

ac

Square Miles

0.5

sq mi

320 ac = 0.5 sq mi

sq mi = ac ÷ 640

Acres to Square Miles: 1 ac equals 0.001563 sq mi. To convert acres to square miles, multiply by 0.001563 (sq mi = ac ÷ 640). For example, 10 ac = 0.015625 sq mi.

How to Convert Acres to Square Miles

To convert from acres to square miles, multiply the value by 0.001563. The conversion is linear, meaning doubling the input doubles the output.

Conversion Formula

  • Acres to Square Miles: sq mi = ac ÷ 640
  • Square Miles to Acres: ac = sq mi × 640

Acres to Square Miles Conversion Chart

Acres (ac)Square Miles (sq mi)
0.10.000156
0.250.000391
0.50.000781
10.001563
20.003125
30.004688
50.007813
100.015625
200.03125
250.039063
500.078125
1000.15625
2500.390625
10001.5625

Understanding the Units

What is an Acre?

An acre equals exactly 4,046.8564224 square meters, or 43,560 square feet.

From Old English æcer ("field"), historically the area a yoke of oxen could plow in a day.

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FAQ

How many acres are in a square mile?

One square mile equals exactly 640 acres.

How do I convert acres to square miles?

Divide the number of acres by 640. For example, 320 acres ÷ 640 = 0.5 square miles.

Why are there 640 acres in a square mile?

A mile is 80 chains long, and a square mile is 80 × 80 = 6,400 square chains. Since one acre is 10 square chains, one square mile contains 640 acres.

How many acres is a section of land?

A section of land is one square mile, which equals 640 acres. Townships in the US Public Land Survey System are divided into 36 sections.

How many square miles are in 1 acr?

1 ac equals 0.001563 sq mi.

How do you convert acres to square miles?

Multiply the acr value by 0.001563. Formula: sq mi = ac ÷ 640.

How many square miles are in 5 acres?

5 ac = 0.007813 sq mi.

How do you convert square miles back to acres?

Use the inverse formula: ac = sq mi × 640. For example, 1 sq mi = 640 ac.