Square miles to acres
Type a value in square miles to see it in acres straight away, or type in the second box to convert back.
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Processing and privacy: The result is calculated inside your browser and your data is not sent to any server.
How to use it
- Type the value in the square miles box.
- Read the result in acres as you type, and pick the precision you need.
- Swap the direction to convert back, or copy the result.
How it is calculated
ac = mi² × 640
Multiply the value in square miles by 640 to get acres.
Example
To convert 25 mi² to acres: 25 × 640 = 16,000 ac.
Conversion table
| Square miles (mi²) | Acres (ac) |
|---|---|
| 1 | 640 |
| 2 | 1,280 |
| 3 | 1,920 |
| 5 | 3,200 |
| 10 | 6,400 |
| 20 | 12,800 |
| 25 | 16,000 |
| 50 | 32,000 |
| 100 | 64,000 |
| 250 | 160,000 |
| 500 | 320,000 |
| 1,000 | 640,000 |
About the units
- Square mile
- A square mile is 640 acres, exactly 2,589,988.110336 square meters.
- Acre
- The international acre is 43,560 square feet, exactly 4046.8564224 square meters, used for land in the US and UK.
Limits and caveats
- Results are rounded for display and computed with the browser's floating point precision (about 15 significant digits).
- Both unit factors are exact by their official definitions.
Questions about this tool
How many acres are in one square mile?
1 mi² = 640 ac exactly.
How do I convert square miles to acres?
Use ac = mi² × 640. For example, 25 mi² = 16,000 ac.
How many square miles are in one acre?
1 ac = 0.0015625 mi².
How do I convert square meters to square feet?
Divide the square meters by 0.09290304, or multiply by about 10.7639. The factor is exact because a foot is exactly 0.3048 m.
Are the dunam, feddan and acre the same size?
No. A metric dunam is 1000 m², an Iraqi dunam 2500 m², an Egyptian feddan about 4200.83 m² and an acre 4046.8564224 m².