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Convert square miles to square kilometers instantly with our free online calculator. Essential for geography, comparing country and state sizes, national park areas, travel planning, and cartography.
2.58999
sq km per sq mi
0.386102
sq mi per sq km
640 acres
per square mile
Formula: Square Kilometers = Square Miles x 2.58999
| Square Miles | Square Kilometers | Context |
|---|---|---|
| 0.5 sq mi | 1.295 sq km | Small island or city park |
| 1 sq mi | 2.590 sq km | Standard reference (640 acres) |
| 5 sq mi | 12.95 sq km | Small town area |
| 10 sq mi | 25.90 sq km | Large town or small city |
| 25 sq mi | 64.75 sq km | Manhattan island area |
| 50 sq mi | 129.5 sq km | Mid-size city (e.g., San Francisco) |
| 100 sq mi | 259.0 sq km | Large city area |
| 250 sq mi | 647.5 sq km | Small national park |
| 500 sq mi | 1,295 sq km | Large metro area |
| 1,000 sq mi | 2,590 sq km | Average US county |
| 3,471 sq mi | 8,990 sq km | Yellowstone National Park |
| 5,000 sq mi | 12,950 sq km | Mid-size US state region |
| 10,000 sq mi | 25,900 sq km | State of Maryland |
| 100,000 sq mi | 258,999 sq km | State of Colorado |
| 268,596 sq mi | 695,662 sq km | State of Texas |
| 3,796,742 sq mi | 9,833,520 sq km | Total area of the United States |
A square mile (symbol: sq mi or mi²) is a unit of area used in the United States and a few other countries that still follow the imperial system. It represents the area of a square with sides each measuring one mile (5,280 feet or 1,609.344 meters). One square mile contains exactly 640 acres or 27,878,400 square feet. In the US Public Land Survey System, a "section" of land is defined as exactly one square mile, and a "township" is 36 sections (36 sq mi). Square miles are the standard unit for reporting state, county, and city areas throughout the United States.
A square kilometer (symbol: sq km or km²) is the metric unit of area equal to the area of a square with sides of one kilometer (1,000 meters). One square kilometer contains 1,000,000 square meters or 100 hectares. It is the standard unit for expressing geographic areas in virtually every country outside the United States. International organizations such as the United Nations, the World Bank, and the CIA World Factbook all report country areas in square kilometers.
The relationship between these units is: 1 square mile = 2.58999 square kilometers, or conversely, 1 square kilometer = 0.386102 square miles. This factor is derived from the linear conversion of 1 mile = 1.609344 kilometers, squared (1.609344² = 2.589988). Understanding this conversion is essential for interpreting geographic data, comparing country sizes, planning travel across borders, and working with international mapping standards.
The formula is straightforward: Square Kilometers = Square Miles x 2.58999. Multiply the number of square miles by the conversion factor 2.58999 to get the equivalent area in square kilometers.
Question: Yellowstone covers about 3,471 square miles. How large is that in square kilometers?
That is roughly the size of Puerto Rico or slightly smaller than Lebanon.
Question: Texas has an area of 268,596 square miles. What is that in square kilometers?
For comparison, France is about 643,801 sq km, so Texas is roughly 8% larger than France.
Question: Los Angeles covers about 503 square miles. Convert to square kilometers.
For a quick estimate, multiply square miles by 2.6 (slightly more than the exact factor of 2.58999). This gives you a result within 0.04% accuracy. For example: 100 sq mi x 2.6 = 260 sq km (exact: 259.0). Another trick: multiply by 2.5 and then add 4% of the original. So 1,000 sq mi x 2.5 = 2,500, plus 4% of 1,000 (40) gives 2,540 + 50 = 2,590 sq km. For very rough estimates, simply multiply by 2.5 to get a figure that is within about 3.5% of the exact answer.
| State | Square Miles | Square Kilometers |
|---|---|---|
| Rhode Island | 1,545 | 4,001 |
| Connecticut | 5,543 | 14,357 |
| Maryland | 12,407 | 32,133 |
| West Virginia | 24,230 | 62,756 |
| Indiana | 36,420 | 94,328 |
| Colorado | 104,094 | 269,602 |
| Montana | 147,040 | 380,831 |
| Texas | 268,596 | 695,662 |
| Alaska | 665,384 | 1,723,337 |
| Country | Square Miles | Square Kilometers |
|---|---|---|
| Vatican City | 0.17 | 0.44 |
| Monaco | 0.78 | 2.02 |
| Singapore | 281 | 728 |
| Jamaica | 4,244 | 10,991 |
| Israel | 8,550 | 22,145 |
| United Kingdom | 93,628 | 242,495 |
| France | 248,573 | 643,801 |
| India | 1,269,219 | 3,287,263 |
| Canada | 3,855,103 | 9,984,670 |
| Russia | 6,601,670 | 17,098,242 |
| Park / Natural Area | Square Miles | Square Kilometers |
|---|---|---|
| Hot Springs National Park | 8.5 | 22 |
| Zion National Park | 229 | 593 |
| Grand Canyon National Park | 1,904 | 4,931 |
| Yellowstone National Park | 3,471 | 8,990 |
| Death Valley National Park | 5,270 | 13,650 |
| Denali National Park | 9,446 | 24,464 |
| Wrangell-St. Elias (largest US) | 20,587 | 53,321 |
| Serengeti National Park (Tanzania) | 5,700 | 14,763 |
| Amazon Rainforest | 2,123,562 | 5,500,000 |
World atlases, encyclopedias, and academic textbooks predominantly report country and region sizes in square kilometers. American students, teachers, and researchers need to convert from square miles to understand and compare geographic data presented in international sources.
International travel guides, distance markers, and GPS systems outside the US use kilometers. Understanding the sq mi to sq km relationship helps travelers appreciate the scale of regions they are visiting and plan routes when road signs and maps use metric units.
Deforestation rates, wildfire burn areas, ice sheet extent, and conservation zone sizes are reported in square kilometers by international scientific bodies. Journalists and policy makers in the US must convert these figures to square miles for domestic audiences.
Geographic Information Systems (GIS) professionals frequently work across measurement systems. Satellite imagery, topographic datasets, and spatial databases from international sources use square kilometers, requiring conversion when integrating with US-based imperial datasets.
Since 1 mile = 1.609344 km, you must square this to get the area factor: 1.609344² = 2.58999. Do not simply multiply by 1.6 for area conversions.
For back-of-the-envelope estimates, multiplying by 2.6 gives results within 0.04% of the exact value. Quick enough for conversations and rough comparisons.
Square miles to square kilometers requires multiplying by 2.58999. Dividing by 2.58999 converts the wrong direction (sq km to sq mi). The sq km result should always be larger.
A common mistake is multiplying sq mi by 1.609 instead of 2.58999. The linear factor only works for distance (miles to km), not for area. Always use the squared factor for area conversions.
While "square miles" and "miles squared" mean the same thing mathematically, saying "5 miles squared" can be misheard as "5 miles, squared" (meaning 25 sq mi). Always say "5 square miles" for clarity.
One square mile equals exactly 2.58999 square kilometers. A square mile is about 2.6 times larger than a square kilometer. To convert any number of square miles to square kilometers, multiply by 2.58999.
A square mile is larger than a square kilometer. One square mile equals approximately 2.59 square kilometers. A square mile is 5,280 feet on each side (27,878,400 sq ft), while a square kilometer is 1,000 meters on each side (1,000,000 sq m).
Multiply the number of square miles by 2.58999. For example: 10 sq mi x 2.58999 = 25.8999 sq km. For a quick mental estimate, multiply by 2.6, which gives results accurate to within 0.04%.
One square mile equals 640 acres, 27,878,400 square feet, or about 2.59 square kilometers. For perspective, Manhattan is about 23 square miles, and a typical US county might range from 200 to 2,000 square miles.
The United States uses the imperial/US customary system inherited from Britain, which includes miles and square miles. Most other countries adopted the metric system, using kilometers and square kilometers. International scientific publications and organizations like the UN use square kilometers as the standard.
Divide the number of square kilometers by 2.58999, or equivalently multiply by 0.386102. For example: 100 sq km / 2.58999 = 38.61 sq mi. For a quick estimate, divide by 2.6 or multiply by 0.39.
The total area of the United States is approximately 3,796,742 square miles or 9,833,520 square kilometers, making it the third or fourth largest country in the world depending on how area is measured.
The exact conversion is 1 square mile = 2.589988110336 square kilometers, derived from 1 mile = 1.609344 kilometers (squared). The commonly used factor 2.58999 is rounded to five decimal places, which is accurate enough for virtually all practical purposes.
This calculator uses the internationally recognized conversion factor of 1 square mile = 2.589988110336 square kilometers (derived from 1 mile = 1.609344 km). For official surveys, legal land descriptions, and government documents, always verify conversions with authoritative sources such as the National Geodetic Survey or your jurisdiction's official measurement standards.