Square Mile to Acre Converter
Quickly and accurately convert area measurements from square miles to acres with our free online Square Mile to Acre Converter. Perfect for geography, real estate, land surveys, and property development.
Common Conversions
| Square Miles (sq mi) | Acres |
|---|---|
| 0.1 sq mi | 64 acres |
| 0.25 sq mi | 160 acres |
| 0.5 sq mi | 320 acres |
| 1 sq mi | 640 acres |
| 2 sq mi | 1,280 acres |
| 5 sq mi | 3,200 acres |
| 10 sq mi | 6,400 acres |
| 100 sq mi | 64,000 acres |
How It Works
Converting from square miles (sq mi) to acres is a common area conversion, especially in geography, real estate, and land surveying. This conversion is particularly useful in the United States where both units are frequently used for large land areas.
Conversion Formula:
1 square mile = 640 acres
To convert square miles to acres, multiply the square mile value by 640:
Acres = Square Miles × 640
Example Calculation:
To convert 2.5 square miles to acres:
Acres = 2.5 sq mi × 640 = 1,600 acres
Our converter handles this calculation automatically and provides results with up to 9 decimal places for precision. It also formats the result to remove unnecessary trailing zeros for better readability.
Frequently Asked Questions
What is a square mile?
A square mile is a unit of area equal to the area of a square with sides of 1 mile. It’s commonly used for measuring large areas of land, such as cities, counties, and states. One square mile is equal to 640 acres, 27,878,400 square feet, or 2.59 square kilometers.
What is an acre?
An acre is an imperial unit of area equal to 43,560 square feet or 4,840 square yards. It’s commonly used in the United States, United Kingdom, and other countries that follow the imperial system for measuring land area, especially in agriculture, real estate, and land development.
Why would I need to convert square miles to acres?
This conversion is commonly needed when dealing with large land areas, such as ranches, farms, forests, or when working with geographic data, city planning, or environmental studies. While square miles are used for very large areas, acres are more commonly used in property transactions and land management.
How accurate is this converter?
Our converter uses the standard conversion factor of 640 acres per square mile, which is the officially recognized conversion rate. The calculator can display results with up to 9 decimal places for high precision needs.
What is the historical significance of 640 acres in one square mile?
The relationship between square miles and acres comes from the Public Land Survey System established in the United States in 1785. This system divided land into townships of 6 square miles, which were further divided into 36 sections of 1 square mile (640 acres) each. A quarter section (160 acres) was the standard homestead plot offered to settlers under the Homestead Act of 1862.
How do I convert acres back to square miles?
To convert from acres to square miles, divide the acre value by 640. Alternatively, you can use our Acre to Square Mile Converter for quick and accurate conversions.