Convert Square Miles to Acres
1 mi² = 640 ac
Conversion Table
| square miles (mi²) | acres (ac) |
|---|---|
| 0.5 | 320 |
| 1 | 640 |
| 2 | 1280 |
| 5 | 3200 |
| 10 | 6399.99 |
| 25 | 15999.99 |
| 50 | 31999.97 |
| 100 | 63999.94 |
| 250 | 159999.85 |
| 500 | 319999.7 |
| 1000 | 639999.41 |
How to Convert square miles to acres
To convert square miles to acres, multiply the value by the conversion factor:
For example: 10 mi² = 6399.99 ac
About square miles and acres
The Conversion Formula
To convert square miles to acres, multiply the value by the conversion factor: 1 mi² = 640 ac. For a worked example, suppose you need to convert 25 mi² to acres: 25 × 640 = 15999.99 ac. To convert in the opposite direction, divide by 640, or equivalently multiply by 0.0015625.
About square miles
The square mile is an imperial unit of area equal to 640 acres. In the US, it is famously linked to the 'section' in the Public Land Survey System, which divided the American West into 1-mile grids. It is the standard for reporting town and county sizes in the US and UK. square miles are commonly used in City and state sizes (US), Population density (people/sq mi), Large ranch sales, and Weather systems, US Census data.
The island of Manhattan is roughly 23 square miles.
About acres
The acre's origins are agricultural: it was originally defined as the amount of land a yoke of oxen could plow in a single day. This 'furlong' (furrow long) by 'chain' definition standardized land ownership in medieval England. Today, the acre remains the king of land measurement in the US and UK. There are 640 acres in a square mile. acres are commonly used in US Farm land, Residential lots (US), Public parks (US/UK), and Golf courses, Deforestation stats (US media).
An American football field (including end zones) is about 1.32 acres.
When Would You Convert square miles to acres?
Converting between square miles and acres is one of the most common area conversions. You might need this conversion when working with international specifications, following instructions written for a different measurement system, or comparing values across different standards. Having the conversion factor (1 mi² = 640 ac) memorized or bookmarked can save time in professional and everyday contexts alike.