Enter the number of acres into the calculator to convert the area into square miles. This calculator provides a quick conversion based on the standard measurement that 1 square mile is equal to 640 acres.

Acres to Square Miles Calculator

Enter one value to calculate the other

Acres ↔ Square Miles Conversion Table
Acres to Square Miles Square Miles to Acres
1 acre = 0.0015625 sq mi0.01 sq mi = 6.4 acres
2 acres = 0.003125 sq mi0.02 sq mi = 12.8 acres
5 acres = 0.0078125 sq mi0.05 sq mi = 32 acres
10 acres = 0.015625 sq mi0.1 sq mi = 64 acres
20 acres = 0.03125 sq mi0.125 sq mi = 80 acres
40 acres = 0.0625 sq mi0.25 sq mi = 160 acres
50 acres = 0.078125 sq mi0.5 sq mi = 320 acres
80 acres = 0.125 sq mi0.75 sq mi = 480 acres
100 acres = 0.15625 sq mi1 sq mi = 640 acres
120 acres = 0.1875 sq mi1.5 sq mi = 960 acres
160 acres = 0.25 sq mi2 sq mi = 1,280 acres
200 acres = 0.3125 sq mi2.5 sq mi = 1,600 acres
320 acres = 0.5 sq mi5 sq mi = 3,200 acres
400 acres = 0.625 sq mi10 sq mi = 6,400 acres
500 acres = 0.78125 sq mi20 sq mi = 12,800 acres
640 acres = 1 sq mi50 sq mi = 32,000 acres
1,000 acres = 1.5625 sq mi100 sq mi = 64,000 acres
1,500 acres = 2.34375 sq mi150 sq mi = 96,000 acres
2,000 acres = 3.125 sq mi200 sq mi = 128,000 acres
5,000 acres = 7.8125 sq mi500 sq mi = 320,000 acres
Formulas: sq mi = acres ÷ 640 and acres = sq mi × 640.

Related Calculators

Acres to Square Miles Formula

The formula used to convert acres to square miles is:

SM = A / 640

Variables:

  • SM is the area in square miles
  • A is the area in acres

To calculate the area in square miles, divide the area in acres by 640.

What is an Acre?

An acre is a unit of area commonly used in the United States and the United Kingdom. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to 1/640 of a square mile, about 40% of a hectare, or 4,840 square yards.

How to Calculate Acres to Square Miles?

The following steps outline how to calculate the area in square miles from acres.


  1. First, determine the area in acres (A).
  2. Next, use the formula SM = A / 640.
  3. Finally, calculate the area in square miles (SM).
  4. After inserting the variable and calculating the result, check your answer with the calculator above.

Example Problem:

Use the following variable as an example problem to test your knowledge.

Area in acres (A) = 1280 acres