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Square Mile to Square Kilometer Conversion Calculator: Free Online Tool

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

Square Mile to Square Kilometer Calculator

mi²
Square Mile
km²
Square Kilometer

How to Use the Calculator:

  1. Enter the value you want to convert in the 'From' field (Square Mile).
  2. The converted value in Square Kilometer 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 Square Kilometer

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

Formula:

1 Square Mile = 2.589988 square kilometers

Example Calculation:

Convert 10 square miles: 10 × 2.589988 = 25.89988 square kilometers

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 Square Kilometer?

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 square kilometer (symbol: km²) is a decimal multiple of the SI unit of area, the square meter. It represents the area of a square with sides that are each one kilometer long (1 km² = 1,000,000 m²).

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

History of the Square Mile and Square Kilometer

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.

As a multiple of the square meter, the square kilometer came into use alongside the metric system for measuring large areas like land masses, cities, and countries. Its adoption followed the establishment of the kilometer as a standard unit of distance.

Common Uses for square miles and square kilometers

Explore the typical applications for both Square Mile (imperial/US) and Square Kilometer (metric) 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 square kilometers

  • Geography & Cartography: Standard unit for measuring the land area of cities, regions, countries, and continents.
  • Demographics: Used to calculate population density (people per km²).
  • Environmental Science: Measuring the extent of forests, deserts, lakes, or areas affected by environmental changes (e.g., deforestation, wildfires).
  • Urban Planning: Assessing land use and zoning areas within large municipalities.

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 Square Kilometer (km²)

How many square meters are in a square kilometer?

There are 1,000,000 square meters in one square kilometer (1 km x 1 km = 1000 m x 1000 m).

How many square miles are in a square kilometer?

One square kilometer is approximately 0.3861 square miles.

Is km² used for small areas?

No, it's generally used for very large areas like cities or countries. Square meters, hectares, or acres are used for smaller plots.

Is km² an official SI unit?

While based on the SI unit meter, the official SI derived unit for area is the square meter (m²). However, the square kilometer is a standard metric unit widely accepted for use with SI.

Conversion Table: Square Mile to Square Kilometer

Square Mile (mi²)Square Kilometer (km²)
12.59
512.95
1025.9
2564.75
50129.499
100258.999
5001,294.994
1,0002,589.988

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 CentimeterSquare Mile to Square MillimeterSquare Mile to Square InchSquare Mile to Square FootSquare Mile to Square YardSquare Mile to AcreSquare 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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