# Convert square miles to acres

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

square miles (sq mi)
1 square miles = 640 acres

## Precise decimal and fraction answers

The conversion in acres rounded to six significant decimal places is 1 sq mi = 640.000000 acre. The precise fraction answer is 640 0/1 acre.

### Decimal Precision

Conversion from one to ten decimal places

• 1 sq mi = 640.0 acre
• 1 sq mi = 640.00 acre
• 1 sq mi = 640.000 acre
• 1 sq mi = 640.0000 acre
• 1 sq mi = 640.00000 acre
• 1 sq mi = 640.000000 acre
• 1 sq mi = 640.0000000 acre
• 1 sq mi = 640.00000000 acre
• 1 sq mi = 640.000000000 acre
• 1 sq mi = 640.0000000000 acre

## Square miles to acres conversion factor and formulas

Formula

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

### Multiplication

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

### Division

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

When converting from from square miles to acres, 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 acres to square miles instead.

## 1 square miles to other area units

### Metric

• 1 sq mi = 258.999 ha
• 1 sq mi = 2.59 km2
• 1 sq mi = 2,589,988.11 m2
• 1 sq mi = 2.59×108 dm2
• 1 sq mi = 2.59×1010 cm2
• 1 sq mi = 2.59×1012 mm2
• 1 sq mi = 2.59×1018 µ2
• 1 sq mi = 2.59×1024 nm2

### Imperial/U.S.

• 1 sq mi = 640 acre
• 1 sq mi = 1 sq mi
• 1 sq mi = 3,097,600 sq yd
• 1 sq mi = 2.788×107 sq ft
• 1 sq mi = 4.014×109 sq in

## References and Citations

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

## Square miles to acres conversion table

sq mi acre
1 sq mi 640 acre
2 sq mi 1,280 acre
3 sq mi 1,920 acre
4 sq mi 2,560 acre
5 sq mi 3,200 acre
6 sq mi 3,840 acre
7 sq mi 4,480 acre
8 sq mi 5,120 acre
9 sq mi 5,760 acre
10 sq mi 6,400 acre
sq mi acre
20 sq mi 12,800 acre
30 sq mi 19,200 acre
40 sq mi 25,600 acre
50 sq mi 32,000 acre
60 sq mi 38,400 acre
70 sq mi 44,800 acre
80 sq mi 51,200 acre
90 sq mi 57,600 acre
100 sq mi 64,000 acre
1,000 sq mi 640,000 acre