Acres to Square Miles Calculator
Convert land area between acres and square miles using the standard U.S. survey relationship of 640 acres per square mile.
Converting acres to square miles
This calculator converts between acres and square miles using the standard U.S. survey relationship: one square mile equals exactly 640 acres. This figure comes from the historical land-survey system where a square mile section of land was divided into 640 one-acre parcels.
To convert acres to square miles, divide the acre value by 640. To go the other way, multiply the square mile value by 640. The tool also shows the equivalent in hectares and square kilometers for reference against metric land measurements.
This calculator is intended for general planning and educational purposes. For legal property boundaries or official land records, consult a licensed surveyor.