Convert Square Miles to Acres

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

Results in Acres:
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1 sq mi = 640 ac

How to Convert Square Miles to Acres

Calculators can be used to convert measurements from one unit to another

Convert square miles to acres with this simple formula:

acres = square miles × 640

Converting a square mile area measurement to an acre measurement involves multiplying the area by the conversion ratio to find the result. One square mile is equal to 640 acres, so to convert simply multiply by 640.

For example, here's how to convert 5 square miles to acres using the formula above.
5 sq mi = (5 × 640) = 3,200 ac

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

Square miles and acres are both units used to measure area. Learn more about area and find more area measurement conversion calculators. Square miles are an imperial measurement and can be abbreviated as sq mi, for example 1 sq mi. Acres are an imperial measurement and can be abbreviated as ac, for example 1 ac.

square miles and acres are units used to measure area
Convert Acres to Square Miles

Square Mile Measurements and Equivalent Acre Conversions

Common square mile values converted to the equivalent acre value
Square Miles Acres
1 sq mi 640 ac
2 sq mi 1,280 ac
3 sq mi 1,920 ac
4 sq mi 2,560 ac
5 sq mi 3,200 ac
6 sq mi 3,840 ac
7 sq mi 4,480 ac
8 sq mi 5,120 ac
9 sq mi 5,760 ac
10 sq mi 6,400 ac
11 sq mi 7,040 ac
12 sq mi 7,680 ac
13 sq mi 8,320 ac
14 sq mi 8,960 ac
15 sq mi 9,600 ac
16 sq mi 10,240 ac
17 sq mi 10,880 ac
18 sq mi 11,520 ac
19 sq mi 12,160 ac
20 sq mi 12,800 ac
21 sq mi 13,440 ac
22 sq mi 14,080 ac
23 sq mi 14,720 ac
24 sq mi 15,360 ac
25 sq mi 16,000 ac
26 sq mi 16,640 ac
27 sq mi 17,280 ac
28 sq mi 17,920 ac
29 sq mi 18,560 ac
30 sq mi 19,200 ac
31 sq mi 19,840 ac
32 sq mi 20,480 ac
33 sq mi 21,120 ac
34 sq mi 21,760 ac
35 sq mi 22,400 ac
36 sq mi 23,040 ac
37 sq mi 23,680 ac
38 sq mi 24,320 ac
39 sq mi 24,960 ac
40 sq mi 25,600 ac

More Square Mile Area Conversions

US Customary
Convert to Square Yards
1 sq mi is equal to 3,097,600 square yards
Convert to Square Feet
1 sq mi is equal to 27,878,400 square feet
Convert to Square Inches
1 sq mi is equal to 4,014,489,599.5 square inches
SI Units
Convert to Square Kilometers
1 sq mi is equal to 2.589988 square kilometers
Convert to Square Meters
1 sq mi is equal to 2,589,988.1 square meters
Convert to Square Centimeters
1 sq mi is equal to 25,899,881,100 square centimeters
Convert to Square Millimeters
1 sq mi is equal to 2,589,988,110,000 square millimeters
Other Metric Units
Convert to Hectares
1 sq mi is equal to 258.998811 hectares
Convert to Ares
1 sq mi is equal to 25,899.9 ares

Unit of Measurement Conversion Made Easy!

There are thousands of units of measure in use across the globe, and converting from one to another can be very difficult since each conversion requires a different formula to derive the result. Our unit of measurement conversion tools are meant to be dead easy. We break the mold of the typical dry and complicated experience. In addition to converting from one measurement to another, we provide the formula so you can see how the conversion is done, use it on you’re own calculator if you need to!

Convert units of length, weight, volume, and area between imperial and metric measures

Understanding the Metric System

The metric system makes it relatively easy to convert from one metric unit to another metric unit. The metric system uses a base unit, think meters or grams, and a prefix such as kilo or milli. The prefixes differ from the base units by differing powers of 10. So to convert within the metric system it’s usually a matter of multiplying or dividing by one of the powers of 10.

Here is a list of some of the common metric prefixes:

  • “kilo” – 1,000x larger
  • “hecto” – 100x larger
  • “deca” – 10x larger
  • “deci” – 10x smaller
  • “centi” – 100x smaller
  • “milli” – 1,000x smaller

There is a helpful mnemonic for remembering the prefixes: “King Henry Died Until Drinking Chocolate Milk.”
The u in Until refers to the base unit.