Acres to Square Miles
Convert acre to mi² quickly with this free online calculator. The page explains the conversion rule, gives practical examples and provides a quick reference table.
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CONVERTED RESULT—
Decimal places
CONVERSION RULE
640 acres equal 1 square mile.
How to use the Acres to Square Miles
- Enter the number you want to convert.
- Confirm the source unit shown beside the input.
- Choose decimal precision if you need more or less detail.
- Read the converted result.
- Copy the result when you need to use it elsewhere.
How the conversion works
640 acres equal 1 square mile.
For a simple fixed-factor conversion, the calculator multiplies the entered value by the stated factor. Temperature scales and certain specialized tools use their specific mathematical relationship instead.
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Common acre to mi² conversions
| acre | mi² |
|---|---|
| 1 acre | 0.001563 mi² |
| 2 acre | 0.003125 mi² |
| 5 acre | 0.007812 mi² |
| 10 acre | 0.015625 mi² |
| 20 acre | 0.03125 mi² |
| 50 acre | 0.078125 mi² |
Example
For example, entering 1 acre gives approximately 0.001563 mi² using the rule above. Change the input to test your own value.
Frequently asked questions
The Acres to Square Miles converts a value from acre to mi² using the conversion relationship described on this page.
Enter your value, review the source and destination units, choose the decimal precision and read or copy the result.
640 acres equal 1 square mile.
Use enough precision for your purpose. Everyday estimates usually need fewer decimal places; technical work may require more.
It can be a useful reference calculation, but safety-critical, regulated, contractual or specialized work should be verified against the applicable authoritative standard.
Accuracy note: This calculator is a practical reference. For regulated, safety-critical or specialized work, verify the result against the applicable standard.
Page reviewed: August 24, 2026.