# Convert acres to square miles

Enter the number of acres you want to convert to square miles in the text box below. The conversion to area in square miles will update as you type.

acres (acre)
1 acres = 0.002 square miles

## Precise decimal and fraction answers

The conversion in square miles rounded to six significant decimal places is 1 acre = 0.00156250 sq mi. The precise fraction answer is 1/640 sq mi.

### Decimal Precision

Conversion from one to ten decimal places

• 1 acre = 0.002 sq mi
• 1 acre = 0.0016 sq mi
• 1 acre = 0.00156 sq mi
• 1 acre = 0.001563 sq mi
• 1 acre = 0.0015625 sq mi
• 1 acre = 0.00156250 sq mi
• 1 acre = 0.001562500 sq mi
• 1 acre = 0.0015625000 sq mi
• 1 acre = 0.00156250000 sq mi
• 1 acre = 0.001562500000 sq mi

## Acres to square miles conversion factor and formulas

Formula

The conversion factor between acres and square miles is 640. This represents the ratio of acres per one square mile. To calculate the value in square miles, we can either divide by the conversion factor or multiply by its inverse.

### Division

To convert from acres to square miles, divide acres by 640.
The formula is expressed as:
acre ÷ 640 = sq mi

### Multiplication

Alternatively we can multiply by the inverse conversion factor to get the same result.
The inverse of 640 is 1/640 or 0.002. To convert from acres to square miles, multiply acres by 0.002.
The formula is expressed as:
acre × 0.002 = sq mi

When converting from from acres to square miles, both units are within the US Customary / UK Imperial system and conversion factors are governed by standards set by the controlling body.

## Reverse this conversion

Convert from square miles to acres instead.

## 1 acres to other area units

### Metric

• 1 acre = 0.405 ha
• 1 acre = 0.004 km2
• 1 acre = 4,046.856 m2
• 1 acre = 404,685.642 dm2
• 1 acre = 4.047×107 cm2
• 1 acre = 4.047×109 mm2
• 1 acre = 4.047×1015 µ2
• 1 acre = 4.047×1021 nm2

### Imperial/U.S.

• 1 acre = 1 acre
• 1 acre = 0.002 sq mi
• 1 acre = 4,840 sq yd
• 1 acre = 43,560 sq ft
• 1 acre = 6,272,640 sq in

## References and Citations

1. National Institute of Standards and Technology (NIST) General Tables of Units of Measurement

## Acres to square miles conversion table

acre sq mi
1 acre 0.002 sq mi
2 acre 0.003 sq mi
3 acre 0.005 sq mi
4 acre 0.006 sq mi
5 acre 0.008 sq mi
6 acre 0.009 sq mi
7 acre 0.011 sq mi
8 acre 0.013 sq mi
9 acre 0.014 sq mi
10 acre 0.016 sq mi
acre sq mi
20 acre 0.031 sq mi
30 acre 0.047 sq mi
40 acre 0.062 sq mi
50 acre 0.078 sq mi
60 acre 0.094 sq mi
70 acre 0.109 sq mi
80 acre 0.125 sq mi
90 acre 0.141 sq mi
100 acre 0.156 sq mi
1,000 acre 1.562 sq mi