Acres to Square Miles Converter
How to convert acres to square miles
square miles = acres ÷ 640
To convert acres to square miles, divide the number of acres by 640.
1 ac = 0.0015625 mi²
Examples
- 1 ac ÷ 640 = 0.0015625 mi²
- One square mile: 640 ac ÷ 640 = 1 mi²
Good to know
One square mile is exactly 640 acres.
This is the international acre. The US survey acre, based on the survey foot that was retired at the end of 2022, is about 4,046.873 m², a difference of roughly 4 parts per million.
Acres to square miles conversion table
| Acres (ac) | Square miles (mi²) |
|---|---|
| 0.25 ac | 0.000390625 mi² |
| 0.5 ac | 0.00078125 mi² |
| 0.75 ac | 0.001171875 mi² |
| 1 ac | 0.0015625 mi² |
| 2 ac | 0.003125 mi² |
| 3 ac | 0.0046875 mi² |
| 4 ac | 0.00625 mi² |
| 5 ac | 0.0078125 mi² |
| 10 ac | 0.015625 mi² |
| 20 ac | 0.03125 mi² |
| 40 ac | 0.0625 mi² |
| 50 ac | 0.078125 mi² |
| 100 ac | 0.15625 mi² |
| 160 ac | 0.25 mi² |
| 500 ac | 0.78125 mi² |
| 640 ac | 1 mi² |
| 1,000 ac | 1.5625 mi² |
Unit definitions
- Acre (ac)
- An acre is 43,560 square feet, exactly 4,046.8564224 square meters. It is the usual unit for land area in the United States and is still common in the United Kingdom.
- Square mile (mi²)
- A square mile is 640 acres, exactly 2,589,988.110336 square meters. It is used in the United States for the areas of cities, counties and states.