Square Kilometers to Square Miles Calculator — Instant km² to mi² Conversion
Convert any square kilometer figure to square miles in real time — free, accurate to four decimals, and built for American readers decoding world geography, travel stats, and international datasets.
Area Conversion CalculatorThe quick answer for 1 Square Kilometers — type any value below for the exact result
Square Kilometers
Square Miles
sq km to sq mi Conversion Formula
To convert square kilometers to square miles, multiply by 0.3861. Since one kilometer equals 0.621371 miles, squaring that length ratio produces the 0.3861 area factor.
Square Kilometers and Square Miles Explained
Square Kilometers (km2)
A square kilometer (sq km, km²) is the metric unit for large territories: a square 1,000 meters (about 0.62 miles) on a side, equal to about 247 acres or 0.3861 square miles. World reference works use it for everything from city cores in the tens of sq km to lakes in the hundreds and small nations like Malta at 316 sq km.
Where it is used: Square kilometers are the standard in geography, demography, ecology, and government statistics worldwide — including the UN and every major international dataset — everywhere except the US.
Origin: The kilometer was formalized in France in 1795 as 1,000 meters; as the metric system spread through the 19th century, its square became the default for large-area reporting.
Square Miles (mi2)
A square mile (sq mi, mi²) is the American large-area unit: a square one statute mile — 5,280 feet — on each side, equal to 640 acres or 2.59 sq km. US geography runs on it, from Manhattan's 22.8 sq mi of land to Yellowstone's 3,471 sq mi and Rhode Island's 1,033.8 sq mi.
Where it is used: Square miles anchor US Census figures, state and county records, national park statistics, and American almanacs.
Origin: An English statute of 1593 fixed the mile at 5,280 feet; American surveyors later laid out the public lands in square-mile sections, embedding the unit in US geography.
Square Kilometers to Square Miles Conversion Table
| Square Kilometers (km2) | Square Miles (mi2) |
|---|---|
| 0.25 km2 | 0.0965250965 mi2 |
| 0.5 km2 | 0.1930501931 mi2 |
| 1 km2 | 0.3861003861 mi2 |
| 1.5 km2 | 0.5791505792 mi2 |
| 2 km2 | 0.7722007722 mi2 |
| 2.5 km2 | 0.9652509653 mi2 |
| 5 km2 | 1.9305019305 mi2 |
| 7.5 km2 | 2.8957528958 mi2 |
| 10 km2 | 3.861003861 mi2 |
| 15 km2 | 5.7915057915 mi2 |
| 20 km2 | 7.722007722 mi2 |
| 25 km2 | 9.6525096525 mi2 |
| 50 km2 | 19.305019305 mi2 |
| 75 km2 | 28.9575289575 mi2 |
| 100 km2 | 38.61003861 mi2 |
| 150 km2 | 57.9150579151 mi2 |
| 200 km2 | 77.2200772201 mi2 |
| 250 km2 | 96.5250965251 mi2 |
| 500 km2 | 193.0501930502 mi2 |
| 1000 km2 | 386.1003861004 mi2 |
Square Miles to Square Kilometers Conversion Table
| Square Miles (mi2) | Square Kilometers (km2) |
|---|---|
| 1 mi2 | 2.59 km2 |
| 2 mi2 | 5.18 km2 |
| 5 mi2 | 12.95 km2 |
| 10 mi2 | 25.9 km2 |
| 20 mi2 | 51.8 km2 |
| 25 mi2 | 64.75 km2 |
| 50 mi2 | 129.5 km2 |
| 100 mi2 | 259 km2 |
| 200 mi2 | 518 km2 |
| 250 mi2 | 647.5 km2 |
| 500 mi2 | 1295 km2 |
Square Kilometers to Square Miles in Everyday Objects
Common real-world examples that make Square Kilometers and Square Miles easy to picture at a glance.
| Square Kilometers (km2) | Square Miles (mi2) | |
|---|---|---|
| Paris city proper | 105.4 km2 | 40.694980695 mi2 |
| Lake Balaton in Hungary | 592 km2 | 228.5714285714 mi2 |
| Gibraltar | 6.8 km2 | 2.6254826255 mi2 |
| Central Park | 3.41 km2 | 1.3166023166 mi2 |
| Liechtenstein | 160 km2 | 61.7760617761 mi2 |
| Malta | 316 km2 | 122.0077220077 mi2 |
| Hyde Park in London | 1.42 km2 | 0.5482625483 mi2 |
When You Need Square Kilometers to Square Miles Conversions
Reading European City Profiles
Barcelona's 101.4 sq km works out to 39.15 sq mi — helping you size it against San Francisco's roughly 47 sq mi of land before you commit to a move or a study-abroad semester.
Lake and Reservoir Comparisons
Lake Balaton at 592 sq km converts to 228.57 sq mi, while Lake Tahoe's 496 sq km is 191.51 sq mi — Hungary's lake comes out about 19% bigger once both figures wear the same unit.
Country Size for US Readers
Liechtenstein's 160 sq km becomes 61.78 sq mi — almost exactly Washington, DC's 61.4 sq mi of land. An entire European nation that fits inside the District.
Administrative District Planning
A 25 sq km planning district is 9.65 sq mi, and a density target of 8,000 residents per sq km reads as about 20,720 per sq mi — right in the range US zoning debates use.
Related Area Conversions
How to Use
-
1
Enter the Area in sq km
Type the square-kilometer figure from your metric source — say, 105.4 sq km for the city of Paris ahead of your trip
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2
See the Square Miles
The result appears instantly: 105.4 sq km = 40.69 sq mi — Paris, sized on a scale American readers can actually picture
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3
Copy or Reverse
Paste the result into your paper or itinerary, or hit Swap to turn a US figure like Yellowstone's 3,471 sq mi back into square kilometers
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4
Check the Table
Scan for anchors like 50 sq km = 19.31 sq mi (a bit bigger than Berkeley, CA) and 250 sq km = 96.53 sq mi (roughly Arlington, Texas) while comparing places
Why Use Be Converter?
Instant Conversion
Results appear in real time as you type — perfect when you're fact-checking a travel blog, cramming for a geography quiz, or mid-conversation about your Europe trip
Precision Guaranteed
Runs the exact 0.3861 factor (0.621371 miles per kilometer, squared) on every input, so your numbers match US Census tables and textbooks
Handy Reference Table
Built-in anchors: 10 sq km = 3.861 sq mi, 100 sq km = 38.61 sq mi, 1,000 sq km = 386.1 sq mi — size up any world figure at a glance
Swap with One Click
One click flips the tool to sq mi to sq km — handy when a US county, park, or state figure needs to appear in a metric-format report
Free & Unlimited
No account, no usage caps. Convert every country, lake, and city figure on your research list — always free
Completely Private
All math runs locally in your browser. Whatever areas you're converting never leave your device
Frequently Asked Questions
How many square miles are in 1 square kilometer?
How do I convert 10 sq km to sq mi?
What is 100 sq km in square miles?
Is a square kilometer smaller than a square mile?
Why do European city stats use square kilometers?
How many sq mi is Paris?
How many square miles is 50 sq km?
How many sq km are in 1 square mile?
About Square Kilometers to Square Miles Converter
Our free square kilometers to square miles converter helps American readers make sense of a world measured in metric. Foreign capitals, European lakes, Caribbean islands, and international datasets all report area in square kilometers, while US maps, Census tables, and almanacs run on square miles. Whether you're planning an overseas trip, fact-checking an article, or finishing a geography assignment, this tool applies the exact 0.3861 conversion factor on every keystroke — no signup, nothing getting in your way.
Expert Tips for sq km to sq mi Conversion
The area factor is the square of the length ratio: 1 km = 0.621371 mi, and 0.621371² = 0.3861 — lengths and areas never share the same conversion number.
Keep US-friendly anchors handy: Paris is 105.4 sq km = 40.69 sq mi, Malta is 316 sq km = 122.01 sq mi (about twice Washington, DC), and Liechtenstein is 160 sq km = 61.78 sq mi — nearly identical to DC's 61.4 sq mi of land.
For lakes, convert first, compare second: Hungary's Lake Balaton (592 sq km) is 228.57 sq mi — about 19% bigger than Lake Tahoe's 496 sq km (191.51 sq mi).
Mental shortcut: divide sq km by 2.6. A 200 sq km metro area comes out to roughly 77 sq mi against the exact 77.22 — plenty close for road-trip conversation.
Population density flips the same factor: 8,000 people per sq km is 8,000 ÷ 0.3861 ≈ 20,720 per sq mi — a bit denser than San Francisco's roughly 18,600 per sq mi.