Square Kilometer to Square Inch Conversion Calculator: Free Online Tool

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

From:

Square Kilometer

To:

Square Inch

How to Use the Calculator:

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

How to Convert Square Kilometer to Square Inch

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

Formula:

1 Square Kilometer = 1550003000 square inches

Example Calculation:

Convert 10 square kilometers: 10 × 1550003000 = 15500030000 square inches

Disclaimer: For Reference Only

These conversion results are provided for informational purposes only. While we strive for accuracy, we make no guarantees regarding the precision of these results, especially for conversions involving extremely large or small numbers which may be subject to the inherent limitations of standard computer floating-point arithmetic.

Not for professional use. Results should be verified before use in any critical application. View our Terms of Service for more information.

What is a Square Kilometer and a Square Inch?

The Square Kilometer (symbol: km² or sq km) is a multiple of the square meter (m²), the base unit of area in the International System of Units (SI). It represents the area of a square whose sides measure exactly one kilometer (km) in length.

Key relationships:

1 km² = 1 kilometer × 1 kilometer
1 km = 1,000 meters (m)
Therefore, 1 km² = (1,000 m) × (1,000 m) = 1,000,000 square meters (m²)
1 km² = 100 hectares (ha) (since 1 hectare = 10,000 m²)

In terms of imperial/US customary units:

1 km² ≈ 0.3861 square miles (mi²)
1 km² ≈ 247.1 acres (ac)

The Square Inch (symbol: in² or sq in) is a unit of area in both the British Imperial and United States customary systems of measurement. It is defined as the area of a square whose sides each measure exactly one inch in length.

Mathematically: 1 in² = 1 inch × 1 inch

It is related to other imperial/US customary area units:

1 square foot (ft²) = 144 in² (since 1 ft = 12 in)
1 square yard (yd²) = 1,296 in² (since 1 yd = 3 ft = 36 in)

In terms of metric units, based on the international inch defined as exactly 25.4 millimeters (mm):

1 in² = (25.4 mm)² = 645.16 mm²
1 in² = (2.54 cm)² = 6.4516 cm²
1 in² = (0.0254 m)² = 0.00064516 m²

Note: The Square Kilometer is part of the metric (SI) system, primarily used globally in science and trade. The Square Inch belongs to the imperial/US customary system.

History of the Square Kilometer and Square Inch

Origin: The square kilometer is derived directly from the kilometer, a unit of length introduced as part of the metric system, which was developed in France during the late 18th century.
Metric System Adoption: The metric system, including the meter and its multiples like the kilometer, was created to provide a standardized, decimal-based system of measurement. As nations began adopting the metric system throughout the 19th and 20th centuries, the square kilometer naturally became the standard unit for expressing large geographical areas.
SI Standard: The International System of Units (SI), formally established in 1960, confirmed the square meter (m²) as the base unit of area. The square kilometer is a widely accepted and commonly used multiple of this base unit, consistent with SI prefixes.
Global Usage: Today, the square kilometer is the predominant unit used worldwide for measuring the land area of countries, large administrative regions, bodies of water, and other significant geographical features.

Origin: The square inch originates from the inch, a fundamental unit of length in the English (later British Imperial and US customary) systems. The concept of measuring area based on squaring a length unit dates back to ancient measurement practices.
Evolution of the Inch: The precise length of the inch itself varied significantly over centuries and by location before the 20th century. Early definitions were often based on barleycorns or thumb widths.
Standardization (International Inch): In 1959, the United States and countries of the Commonwealth of Nations agreed upon the definition of the international yard as exactly 0.9144 meters. This agreement consequently defined the international inch as exactly 25.4 millimeters (mm). This standardization fixed the exact metric equivalent of the square inch as 6.4516 square centimeters (cm²).
Continued Use: Despite widespread global metrication, the square inch remains a common unit in the United States, and to a lesser extent in the United Kingdom and Canada, particularly in certain trades and industries.

Common Uses for square kilometers and square inches

Explore the typical applications for both Square Kilometer (metric) and Square Inch (imperial/US) to understand their common contexts.

Common Uses for square kilometers

The square kilometer is almost exclusively used for measuring large-scale areas:

Geography and Cartography: The standard unit for stating the land or surface area of countries, continents, large islands, administrative divisions (states, provinces), and major cities.
Demography: Essential for calculating population density, typically expressed as inhabitants per square kilometer (people/km²).
Environmental Science: Measuring the extent of large ecosystems (forests, deserts, wetlands), national parks, conservation areas, watersheds, ice sheets, or the area impacted by large-scale environmental events (e.g., oil spills, deforestation).
Urban Planning and Land Management: Quantifying large zones, districts, or total city area in regional planning.
Geology and Planetary Science: Measuring the surface area of large geological formations or the surface areas of planets, moons, and asteroids.
Military and Logistics: Defining large operational areas or zones.

It is too large for measuring individual properties, farms (hectares or acres are preferred), or room sizes (square meters or square feet are used).

Common Uses for square inches

The square inch is primarily used for measuring relatively small areas, especially in specific fields:

Engineering and Manufacturing (US/UK): Specifying the cross-sectional area of wires, beams, or pipes; surface area of small mechanical parts; material stress calculations (often in conjunction with psi - pounds per square inch).
Electronics: Measuring the surface area of components like microchips or circuit boards.
Material Science: Quantifying the area of material samples for testing (e.g., fabric swatches, paper sheets).
Printing and Graphic Design (US): Sometimes used for small image dimensions or layout areas, although points and picas are also common.
Pressure Measurement: Implicitly used as the denominator in the widely used unit of pressure, pounds per square inch (psi).
Retail (Specific Goods): Occasionally used for pricing small, specialized items sold by area (e.g., certain textiles, craft supplies).
Crafts and Hobbies: Measuring small patches of fabric, paper dimensions, or design elements in quilting, scrapbooking, etc.

It is generally too small for measuring room dimensions (square feet are used) or land (acres or square miles are used).

Frequently Asked Questions

Questions About Square Kilometer (km²)

How many square meters are in one square kilometer?

There are exactly 1,000,000 square meters (m²) in one square kilometer. This is calculated as 1,000 meters × 1,000 meters.

How many hectares are in one square kilometer?

There are exactly 100 hectares (ha) in one square kilometer. (1 km² = 1,000,000 m² and 1 ha = 10,000 m²).

How do you convert square kilometers to square miles?

To convert square kilometers to square miles, multiply the area in square kilometers by approximately 0.386102.

Conversion formula: Area [mi²] ≈ Area [km²] × 0.386102
Example: 100 km² ≈ 100 × 0.386102 mi² ≈ 38.61 mi²

Conversely, to convert square miles to square kilometers, multiply by approximately 2.58999.

1 mi² ≈ 2.59 km²

Is the square kilometer an official SI unit?

Strictly speaking, the official SI derived unit for area is the square meter (m²). However, the square kilometer (km²) is formed by combining an SI prefix (kilo-) with the SI base unit (meter) raised to the power of two, making it a standard and fully accepted multiple within the metric system and for use alongside SI units.

What is the difference between a kilometer and a square kilometer?

A kilometer (km) is a unit of length or distance (one dimension). A square kilometer (km²) is a unit of area (two dimensions), representing a square with sides of one kilometer each.

About Square Inch (in²)

How many square inches are in one square foot?

There are exactly 144 square inches in one square foot. This is because 1 square foot is the area of a square with 12-inch sides (12 inches × 12 inches = 144 in²).

How do you convert square inches to square centimeters?

To convert square inches to square centimeters, multiply the area in square inches by 6.4516.

Conversion formula: Area [cm²] = Area [in²] × 6.4516
Example: 10 in² = 10 × 6.4516 cm² = 64.516 cm²

Is the square inch the same as "inches squared"?

Yes, the terms "square inch" (in²) and "inches squared" refer to the same unit of area.

Is the square inch an SI unit?

No, the square inch is not part of the International System of Units (SI). It belongs to the British Imperial and US customary systems. The corresponding SI units for area are the square meter (m²) and its derived units like the square centimeter (cm²) and square millimeter (mm²).

Why is psi (pounds per square inch) so common?

Pounds per square inch (psi) became a standard unit for measuring pressure (force per unit area) in many English-speaking countries, particularly in engineering and industrial applications, due to the established use of the pound for force and the inch for dimensions within the Imperial and US customary systems. While the SI unit for pressure is the Pascal (Pa), psi remains deeply ingrained in many technical fields in the US.

Conversion Table: Square Kilometer to Square Inch

Square Kilometer (km²)	Square Inch (in²)
1	1,550,003,100.006
5	7,750,015,500.031
10	15,500,031,000.062
25	38,750,077,500.155
50	77,500,155,000.31
100	155,000,310,000.62
500	775,001,550,003.1
1,000	1,550,003,100,006.2

All Area Conversions

Square Meter to Square Kilometer Square Meter to Square Centimeter Square Meter to Square Millimeter Square Meter to Square Inch Square Meter to Square Foot Square Meter to Square Yard Square Meter to Square Mile Square Meter to Acre Square Meter to Hectare Square Kilometer to Square Meter Square Kilometer to Square Centimeter Square Kilometer to Square Millimeter Square Kilometer to Square Foot Square Kilometer to Square Yard Square Kilometer to Square Mile Square Kilometer to Acre Square Kilometer to Hectare Square Centimeter to Square Meter Square Centimeter to Square Kilometer Square Centimeter to Square Millimeter Square Centimeter to Square Inch Square Centimeter to Square Foot Square Centimeter to Square Yard Square Centimeter to Square Mile Square Centimeter to Acre Square Centimeter to Hectare Square Millimeter to Square Meter Square Millimeter to Square Kilometer Square Millimeter to Square Centimeter Square Millimeter to Square Inch Square Millimeter to Square Foot Square Millimeter to Square Yard Square Millimeter to Square Mile Square Millimeter to Acre Square Millimeter to Hectare Square Inch to Square Meter Square Inch to Square Kilometer Square Inch to Square Centimeter Square Inch to Square Millimeter Square Inch to Square Foot Square Inch to Square Yard Square Inch to Square Mile Square Inch to Acre Square Inch to Hectare Square Foot to Square Meter Square Foot to Square Kilometer Square Foot to Square Centimeter Square Foot to Square Millimeter Square Foot to Square Inch Square Foot to Square Yard Square Foot to Square Mile Square Foot to Acre Square Foot to Hectare Square Yard to Square Meter Square Yard to Square Kilometer Square Yard to Square Centimeter Square Yard to Square Millimeter Square Yard to Square Inch Square Yard to Square Foot Square Yard to Square Mile Square Yard to Acre Square Yard to Hectare Square Mile to Square Meter Square Mile to Square Kilometer Square Mile to Square Centimeter Square Mile to Square Millimeter Square Mile to Square Inch Square Mile to Square Foot Square Mile to Square Yard Square Mile to Acre Square Mile to Hectare Acre to Square Meter Acre to Square Kilometer Acre to Square Centimeter Acre to Square Millimeter Acre to Square Inch Acre to Square Foot Acre to Square Yard Acre to Square Mile Acre to Hectare Hectare to Square Meter Hectare to Square Kilometer Hectare to Square Centimeter Hectare to Square Millimeter Hectare to Square Inch Hectare to Square Foot Hectare to Square Yard Hectare to Square Mile Hectare to Acre