How to convert acres to square miles
To convert a measurement in acres to square miles, multiply the value by 0.0015625. The conversion factor comes from the relationship between both units and the square meter.
For example, to convert 5 ac to square miles: 5 × 0.0015625 = 0.0078125 mi².
What is a acre?
An acre is an imperial and US customary unit of area equal to 43,560 square feet, or about 4,046.86 square meters (roughly 0.405 hectares). The acre originally meant the area a yoke of oxen could plow in a day, standardized as 1 chain by 1 furlong (66 by 660 feet). It remains the standard unit for land and farm area in the US and UK.
Common uses of acres include: Farmland and rural land size; Residential lot and property size in the US; Real estate and development parcels; Sports field and park area references.
What is a square mile?
A square mile is an imperial and US customary unit of area equal to the area of a square one mile on each side, or 640 acres, about 2.59 square kilometers. The square mile is the traditional unit for large land areas in the US and UK. In the US Public Land Survey System, a 'section' is exactly one square mile, the building block of the township grid.
Common uses of square miles include: Areas of US and UK cities and counties; Land survey sections (640 acres); Geographic and census area reporting; Property and ranch land in imperial countries.
Acres to square miles worked examples
Here are some common values converted:
1 ac = 0.0015625 mi² 5 ac = 0.0078125 mi² 10 ac = 0.015625 mi² 50 ac = 0.078125 mi² 100 ac = 0.15625 mi²
Frequently asked questions
How many square miles are in one acre?
One acre (ac) equals 0.0015625 square miles (mi²). Multiply any value in acres by 0.0015625 to convert to square miles.
How do I convert acres to square miles?
Multiply the value in acres by 0.0015625. For example, 5 ac × 0.0015625 = 0.0078125 mi².
How do I convert square miles to acres?
Multiply the value in square miles by 640, or divide by 0.0015625. Use the swap button on the converter above to reverse the direction.
Is the acre to square mile conversion exact?
Yes. Area conversions derive from the exact 1959 international definitions of the meter, yard, and foot, so the factors are exact.
What is the formula for acres to square miles?
The formula is: mi² = ac × 0.0015625. This comes from the definition of both units relative to the square meter.