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Square Mile to Acre Conversion Calculator: Free Online Tool

Convert square miles to acres with our free online area converter.

Square Mile to Acre Calculator

mi²
Square Mile
ac
Acre

How to Use the Calculator:

  1. Enter the value you want to convert in the 'From' field (Square Mile).
  2. The converted value in Acre will appear automatically in the 'To' field.
  3. Use the dropdown menus to select different units within the Area category.
  4. Click the swap button (⇌) to reverse the conversion direction.

How to Convert Square Mile to Acre

Converting Square Mile to Acre involves multiplying the value by a specific conversion factor, as shown in the formula below.

Formula:

1 Square Mile = 640 acres

Example Calculation:

Convert 10 square miles: 10 × 640 = 6400 acres

Note: Conversion factors can sometimes be rounded for display purposes. For precise calculations, always use the full factor or rely on the calculator above.

What is a Square Mile and a Acre?

The square mile (symbol: mi², sq mi) is an imperial and US customary unit of area. It represents the area of a square with sides that are each one statute mile long.

The acre (symbol: ac) is a unit of land area used in the imperial and US customary systems. It is traditionally defined as the area of one chain by one furlong (66 by 660 feet), which is exactly equal to 1/640 of a square mile, 43,560 square feet, or about 4,047 square meters.

Note: The Square Mile is part of the imperial/US customary system, primarily used in the US, UK, and Canada for everyday measurements. The Acre belongs to the imperial/US customary system.

History of the Square Mile and Acre

Derived from the mile, a unit of distance with Roman origins, the square mile became a standard unit for measuring large land areas in the imperial system, particularly within the British Empire and the United States. It's often used for geographic and administrative divisions.

The acre originated in medieval England as the amount of land tillable by one man behind one ox in one day. Its size varied historically but was standardized under the Weights and Measures Act of 1878 in the UK. It remains a common unit for land measurement in several countries, especially for agricultural and large residential plots.

Common Uses for square miles and acres

Explore the typical applications for both Square Mile (imperial/US) and Acre (imperial/US) to understand their common contexts.

Common Uses for square miles

  • Geography & Cartography (US/UK): Used for measuring large land areas such as counties, national parks, large estates, or city limits in countries using the imperial/US customary system.
  • Demographics (US/UK): Calculating population density (people per sq mi) in relevant regions.
  • Surveying: Used in land surveying for large tracts of land.
  • Historical Records: Appears in older land deeds and geographical descriptions in relevant countries.

Common Uses for acres

  • Land Measurement (US/UK etc.): Standard unit for measuring plots of land, especially farms, large residential lots, and undeveloped land in the US, UK, Canada, Australia, India, and other Commonwealth countries.
  • Real Estate: Used in property listings and surveys for land parcels.
  • Agriculture: Common unit for describing farm sizes and field areas.

Frequently Asked Questions

Questions About Square Mile (mi²)

How many acres are in a square mile?

There are exactly 640 acres in one square mile.

How many square feet are in a square mile?

One square mile contains 27,878,400 square feet (5280 feet x 5280 feet).

How many square kilometers are in a square mile?

One square mile is approximately 2.59 square kilometers.

Is the square mile used globally?

No, its use is primarily confined to the United States and other countries that traditionally use the imperial or US customary systems for land measurement. The square kilometer is the more common international standard for large areas.

About Acre (ac)

How big is an acre visually?

An acre is roughly 90% of the size of an American football field (including the end zones).

How many square feet are in an acre?

There are exactly 43,560 square feet in one acre.

How many acres are in a hectare?

One hectare contains approximately 2.471 acres.

Is the acre used worldwide?

While common in the US, UK, and Commonwealth countries, it is not part of the metric system (SI) and is less common globally than the hectare or square meter for land measurement.

Conversion Table: Square Mile to Acre

Square Mile (mi²)Acre (ac)
1640
53,200
106,400
2516,000
5032,000
10064,000
500320,000
1,000640,000

All Area Conversions

Square Meter to Square KilometerSquare Meter to Square CentimeterSquare Meter to Square MillimeterSquare Meter to Square InchSquare Meter to Square FootSquare Meter to Square YardSquare Meter to Square MileSquare Meter to AcreSquare Meter to HectareSquare Kilometer to Square MeterSquare Kilometer to Square CentimeterSquare Kilometer to Square MillimeterSquare Kilometer to Square InchSquare Kilometer to Square FootSquare Kilometer to Square YardSquare Kilometer to Square MileSquare Kilometer to AcreSquare Kilometer to HectareSquare Centimeter to Square MeterSquare Centimeter to Square KilometerSquare Centimeter to Square MillimeterSquare Centimeter to Square InchSquare Centimeter to Square FootSquare Centimeter to Square YardSquare Centimeter to Square MileSquare Centimeter to AcreSquare Centimeter to HectareSquare Millimeter to Square MeterSquare Millimeter to Square KilometerSquare Millimeter to Square CentimeterSquare Millimeter to Square InchSquare Millimeter to Square FootSquare Millimeter to Square YardSquare Millimeter to Square MileSquare Millimeter to AcreSquare Millimeter to HectareSquare Inch to Square MeterSquare Inch to Square KilometerSquare Inch to Square CentimeterSquare Inch to Square MillimeterSquare Inch to Square FootSquare Inch to Square YardSquare Inch to Square MileSquare Inch to AcreSquare Inch to HectareSquare Foot to Square MeterSquare Foot to Square KilometerSquare Foot to Square CentimeterSquare Foot to Square MillimeterSquare Foot to Square InchSquare Foot to Square YardSquare Foot to Square MileSquare Foot to AcreSquare Foot to HectareSquare Yard to Square MeterSquare Yard to Square KilometerSquare Yard to Square CentimeterSquare Yard to Square MillimeterSquare Yard to Square InchSquare Yard to Square FootSquare Yard to Square MileSquare Yard to AcreSquare Yard to HectareSquare Mile to Square MeterSquare Mile to Square KilometerSquare Mile to Square CentimeterSquare Mile to Square MillimeterSquare Mile to Square InchSquare Mile to Square FootSquare Mile to Square YardSquare Mile to HectareAcre to Square MeterAcre to Square KilometerAcre to Square CentimeterAcre to Square MillimeterAcre to Square InchAcre to Square FootAcre to Square YardAcre to Square MileAcre to HectareHectare to Square MeterHectare to Square KilometerHectare to Square CentimeterHectare to Square MillimeterHectare to Square InchHectare to Square FootHectare to Square YardHectare to Square MileHectare to Acre

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