How do you use this tool?
- Enter the area in square kilometers (km²) in the input field.
- The equivalent in square miles (mi²) appears instantly as you type.
- Use the swap button to convert square miles back to square kilometers.
- Scroll to the reference table to benchmark your result against US states and parks.
What This Tool Does
The kittokit Square Kilometers to Square Miles converter translates any area given in km² into the equivalent in mi² (and vice versa) using the exact international factor. The tool is designed for anyone working with international geography data, scientific sources, or foreign news reports who needs to convert to the US customary square mile for intuitive understanding.
Quick reference for common conversions:
| km² | mi² | Reference |
|---|---|---|
| 1 | 0.386 | Approximately Central Park, NYC (3.41 km²) ÷ 3 |
| 10 | 3.861 | A mid-size US airport campus |
| 100 | 38.610 | Roughly Washington, D.C. (159 km²) ÷ 1.6 |
| 1,000 | 386.102 | About the size of Los Angeles city (1,302 km²) |
| 10,000 | 3,861 | Roughly the size of Connecticut (14,357 km²) |
| 100,000 | 38,610 | Comparable to South Dakota (199,905 km²) ÷ 2 |
How It Works
The conversion is a direct multiplication:
mi² = km² × 0.386102159
The factor derives from the definition of the international mile (1 mile = 1.609344 km), squared:
1 mi² = (1.609344)² km² = 2.58998811 km²
Therefore: 1 km² = 1 / 2.58998811 mi² = 0.386102159 mi²
The tool applies the full-precision factor and rounds the display to 3–6 significant figures depending on the input magnitude.
What Are Common Use Cases?
US Geography and Education. Students and educators comparing international country sizes to US states use km² from encyclopedias and Wikipedia, then need mi² to match the familiar US framing.
Travel and national parks. The US National Park Service publishes park acreage and area in both units, but many international travel guides use km². Yellowstone (8,983 km² = 3,468 mi²) and Grand Canyon (4,926 km² = 1,902 mi²) are frequently cited.
Real estate and land investment. Large land parcels in Canada, Mexico, and South America are listed in km² or hectares. US investors converting to acres and square miles can benchmark against familiar domestic land sizes.
Environmental reporting. Wildfire damage, deforestation reports, and flood zones are often reported in km² in international media. US readers convert to mi² to calibrate the scale relative to familiar US geography.
Urban planning. City planners comparing US metro areas against international peers encounter km²-based density and area statistics from the OECD, World Bank, and UN that need conversion for domestic reports.
Sports and events. Some extreme sporting events (ultramarathons, adventure races) describe course areas in km². Participants from the US convert to miles for mental reference.
Science and research. Scientific papers default to SI units. Researchers presenting to US audiences convert km² figures in their presentations.
US state and territory reference table:
| State / Territory | km² | mi² |
|---|---|---|
| Alaska | 1,723,337 | 665,384 |
| Texas | 695,662 | 268,596 |
| California | 423,967 | 163,696 |
| Montana | 380,831 | 147,040 |
| New Mexico | 314,917 | 121,590 |
| Florida | 170,312 | 65,758 |
| New York | 141,297 | 54,555 |
| Pennsylvania | 119,280 | 46,054 |
| Ohio | 116,098 | 44,826 |
| Rhode Island | 4,001 | 1,545 |
Frequently Asked Questions
How does km² compare to acres? 1 km² = 247.105 acres. For small land areas, acres are often more intuitive for US users than square miles (which are large units). This converter focuses on km² to mi²; for hectares to acres, use our dedicated tool.
What is the difference between a square mile and a mile square? They mean the same thing: an area equal to a square with sides 1 mile long. In the US Public Land Survey System, a “section” is 1 square mile = 640 acres.
Why do some sources give area in km² and others in mi²? Most of the world uses the SI metric system, so scientific and international sources default to km². The US, UK (historically), and a few other countries use square miles in everyday contexts. This converter bridges both conventions.
Is the conversion exact? The international mile is defined as exactly 1.609344 km, making the derived factor (0.386102159…) a repeating decimal. The tool uses floating-point arithmetic with sufficient precision for any practical measurement.
Last updated: