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Area Converter

Square Mile to Square Kilometer Converter

Convert Square Mile (sq mi) to Square Kilometer (km²) instantly with our interactive tool, benchmark tables, and detailed unit information.

1 sq mi = 2.5900 km²
Editable
sq mi
Input
Auto-Calculated
km²
Result
Area conversion — instant results

Convert Square Mile to Square Kilometer

1 sq mi = 2.5900 km²
Square Mile (sq mi) Square Kilometer (km²)
1 sq mi 2.589988 km²
5 sq mi 12.949941 km²
10 sq mi 25.899881 km²
25 sq mi 64.749703 km²
50 sq mi 129.499406 km²
100 sq mi 258.998811 km²
500 sq mi 1,294.994055 km²
1,000 sq mi 2,589.98811 km²

Convert Square Kilometer to Square Mile

1 km² = 0.3861 sq mi
Square Kilometer (km²) Square Mile (sq mi)
1 km² 0.386102 sq mi
5 km² 1.930511 sq mi
10 km² 3.861022 sq mi
25 km² 9.652554 sq mi
50 km² 19.305108 sq mi
100 km² 38.610216 sq mi
500 km² 193.051079 sq mi
1,000 km² 386.102159 sq mi

About Square Mile and Square Kilometer

Detailed information about both units of measurement.

IMPERIAL UNIT

Square Mile

sq mi
Definition
A US customary unit of area equal to a square measuring 1 mile on each side.
SI / Standard Information
Defined as 2.589988110336 km². Used for measuring large geographic areas in the US and UK.
Approximate Comparison
A square mile is roughly 640 acres or about 2.6 square kilometers.
Practical Applications
  • US county and state area
  • National park size in the US
  • Large property and ranch measurement
  • City land area in the US
Real-World Examples
  • Manhattan is 22.7 square miles
  • The country of Vatican City is 0.17 square miles
  • Yellowstone National Park is 3,471 square miles
METRIC UNIT

Square Kilometer

km²
Definition
An area of 1 km × 1 km. Used for measuring large geographic regions.
SI / Standard Information
SI-derived unit (km²). 1 km² = 1,000,000 m². Standard unit for country area, city size, and geographic regions worldwide.
Approximate Comparison
A square kilometer is about 140 football fields or roughly 0.386 square miles.
Practical Applications
  • Country and city area measurement
  • Geographic and topographic mapping
  • Environmental conservation area
  • Urban planning and zoning
Real-World Examples
  • Central Park in NYC is 3.41 km²
  • The city of Paris is 105.4 km²
  • The country of Monaco is 2.02 km²

About Converting Square Mile to Square Kilometer

Our Square Mile to Square Kilometer converter provides instant, accurate conversion between these two essential area units. Whether you are working in engineering, construction, education, or everyday area measurement, this tool delivers precise results with zero friction.

The Square Mile (sq mi) is a imperial unit of area. A US customary unit of area equal to a square measuring 1 mile on each side. A square mile is roughly 640 acres or about 2.6 square kilometers.

The Square Kilometer (km²) is a metric unit of area. An area of 1 km × 1 km. Used for measuring large geographic regions. A square kilometer is about 140 football fields or roughly 0.386 square miles.

Conversion Formula & Worked Examples

The conversion between sq mi and km² uses the following mathematical relationship:

Square Kilometer = Square Mile × 2.589988

Square Mile = Square Kilometer × 0.386102

Whether you need to convert for us county and state area or country and city area measurement, our interactive converter provides instant, accurate results.

Example

1 sq mi

=

2.59 km²

Example

5 sq mi

=

12.9499 km²

Example

10 sq mi

=

25.8999 km²

Reverse Direction

Need to convert Square Kilometer back into Square Mile?

Switch conversion direction to view Square Kilometer → Square Mile tables, benchmarks, and detailed info.

Open Square Kilometer → Square Mile

Practical Use Cases & Applications

sq mi Square Mile

  • US county and state area
  • National park size in the US
  • Large property and ranch measurement
  • City land area in the US

km² Square Kilometer

  • Country and city area measurement
  • Geographic and topographic mapping
  • Environmental conservation area
  • Urban planning and zoning

Frequently Asked Questions

Common questions about this conversion and related measurement topics.

How do I convert Square Mile to Square Kilometer?
To convert Square Mile (sq mi) to Square Kilometer (km²), multiply the square mile value by the conversion factor. Our converter below handles this instantly — just enter the value in sq mi and the km² result appears in real time.
How many Square Kilometers are in one square mile?
One square mile (sq mi) equals approximately 2.589988 square kilometer (km²). This conversion factor is constant and can be used for any square mile value.
What is the formula to convert sq mi to km²?
The conversion formula is: <strong>Square Kilometer = Square Mile × 2.589988</strong>. For example, 5 sq mi × 2.5900 = 12.9499 km², and 10 sq mi × 2.5900 = 25.8999 km².
Can I convert Square Kilometer back to Square Mile?
Yes! Use the reverse direction on our converter, or visit our dedicated <a href="/area/square-kilometers-to-square-miles/" class="text-accent-teal underline">Square Kilometer to Square Mile converter</a>. The reverse conversion factor is approximately 1 km² = 0.386102 sq mi.
Where is Square Mile commonly used?
US county and state area, National park size in the US, Large property and ranch measurement. A US customary unit of area equal to a square measuring 1 mile on each side.
What is the difference between Square Mile and Square Kilometer?
Square Mile (sq mi) and Square Kilometer (km²) are both units of area. Square Mile belongs to the imperial system, while Square Kilometer belongs to the metric system. Understanding the conversion between them is essential for international work in area measurement.
What are some real-world examples of square-miles and square-kilometers?
Square Mile: Manhattan is 22.7 square miles; The country of Vatican City is 0.17 square miles Square Kilometer: Central Park in NYC is 3.41 km²; The city of Paris is 105.4 km²

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About This Conversion ℹ

This Square Mile to Square Kilometer converter provides accurate, real-time conversions between these two area units.

Both units are among the most commonly used area measurements — rated 6/10 and 7/10 in popularity.

Bookmark this page for quick access to the Square Mile → Square Kilometer converter whenever you need precise unit conversion.

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