Convert area units — square meters, acres, hectares, square feet, square kilometers.
| Unit | Name | Value |
|---|---|---|
| m² | Square Meter | 2589990 |
| km² | Square Kilometer | 2.58999 |
| ha | Hectare | 258.999 |
| ac | Acre | 639.9999 |
| ft² | Square Foot | 27878432 |
| yd² | Square Yard | 3097603.6 |
Common square mile values converted to acre — factor: 1 mi² = 640 ac
| Square Mile (mi²) | Acre (ac) | Context |
|---|---|---|
| 0.1 mi² | 64 ac | Suburb |
| 0.25 mi² | 160 ac | Small town |
| 0.5 mi² | 320 ac | Small town |
| 1 mi² | 640 ac | Small town |
| 2 mi² | 1,280 ac | Small town |
| 5 mi² | 3,200 ac | Medium town |
| 10 mi² | 6,400 ac | Small city |
| 20 mi² | 1.28e+04 ac | Small city |
| 25 mi² | 1.6e+04 ac | Large city |
| 50 mi² | 3.2e+04 ac | Large city |
| 100 mi² | 6.4e+04 ac | Metro area |
| 250 mi² | 1.6e+05 ac | County |
| 500 mi² | 3.2e+05 ac | County |
| 1,000 mi² | 6.4e+05 ac | Small state |
| 5,000 mi² | 3,200,000 ac | Large state |
Converting square mile to acre is common in real estate, agriculture, surveying, and construction. Property listings, land records, and planning documents often use different area units depending on the country or industry — making accurate conversion essential for cross-border transactions and international comparisons.
As a practical reference: 5 mi² = 3200 acre and 10 mi² = 6400 acre. For larger land areas, 100 mi² = 6.4e+04 acre — a common benchmark for farm and estate valuations. The reverse: 1 ac = 0.001563 mi².
All conversions use the internationally recognized factor of exactly 1 mi² = 640 ac. Calculations are performed in IEEE 754 double-precision floating point, giving accuracy to at least 8 significant figures — more than sufficient for any practical application.
Formula: Acre = Square Mile × 639.99941
Multiply any square mile value by 639.99941 to get acre. One square mile equals 639.99941 ac.
Reverse: Square Mile = Acre × 0.0015625014
mi² × 640 = acres. Exact.
One square mile = exactly 640 acres.
Acres ÷ 640 = mi².
Measures and compares geographic region sizes in square miles.
Reports population density in people per square mile.
Tracks fire perimeter and burned area in square miles.
Assesses large land parcels in square miles for master-planned communities.
Defines operational theater and patrol areas in square miles.
Describes scale of disasters and developments in square miles for US audiences.
The square mile is an Imperial unit equal to 640 acres or about 2.59 km². It is used for measuring large territories, cities, and geographic features in the US and UK.
US census data reports city and county areas in square miles. The term 'square mile' also colloquially refers to the City of London financial district.
Interesting fact: Manhattan island in New York City covers about 23 square miles. The entire US is approximately 3.8 million square miles.
The acre is a unit of land area equal to 43,560 square feet or about 4,047 m². Its origins trace to medieval England where it represented the amount of land an ox could plough in a day.
Acres remain the standard land measurement unit in the US, UK, Canada, and India for agriculture, real estate, and property transactions.
Interesting fact: A US football field (including end zones) is about 1.32 acres, and a typical suburban house plot in the US is roughly 0.2 acres.