Square Miles to Square Kilometres Converter — Decode US Land Areas
Convert mi² to km² as you type.
Land & Area Unit Converter - Metric & ImperialReference for one unit; displayed values may be rounded.
Square Miles
Use a dot or comma for decimals, without thousands separators.
Square Kilometers
Display rounding does not improve the accuracy of your original measurement. Very large or very small results use scientific notation.
Method and sourcesq mi to sq km Conversion Formula
To convert square miles to square kilometres, multiply the value by 2.59. A mile is 1.60934 kilometres, and squaring that ratio gives the area factor of 2.59.
Square Miles and Square Kilometers Explained
Square Miles (mi²)
A square mile (sq mi, mi²) is the area of a square one mile — 5,280 feet — on each side, equal to 640 acres or about 2.59 square kilometres. It's the standard large-area unit of American geography: city land areas run from 22.8 sq mi (Manhattan) to 302.6 sq mi (NYC land), counties span hundreds of sq mi, and Rhode Island's 1,033.8 sq mi makes it the smallest US state. It was also Australia's unit of choice before metrication, which is why square miles still surface in old deeds and archives.
Where it is used: Square miles are used by the US Census Bureau, National Park Service statistics, American city planning offices, and English-language almanacs — and they linger in pre-1974 Australian land records, pastoral lease papers, and historical newspapers.
Origin: The statute mile was fixed by an English act of 1593 at 5,280 feet; squaring it later became the standard large-area unit as surveys gridded the American West — and British surveyors carried the same system to Australia, where it served until metric conversion rolled through in the 1970s.
Square Kilometers (km²)
A square kilometre (sq km, km²) is the metric unit for large areas: a square 1,000 metres on each side, containing 100 hectares or one million square metres. It's the language Australian geography speaks — the ACT spans 2,358 sq km, Kangaroo Island 4,405 sq km, and Kakadu 19,816 sq km — making it the natural unit for comparing places at home and abroad.
Where it is used: Square kilometres are standard across Australian government — ABS statistics, council planning schemes, national park fact sheets — as well as in UN databases and scientific literature on land cover and ecology.
Origin: The kilometre entered the French metric system in 1795 as 1,000 metres; its square became the default large-area unit worldwide as metrication spread — and Australia adopted it wholesale during the 1970s conversion program, retiring the square mile for good.
Square Miles to Square Kilometres Conversion Table
Select a value to use it in the calculator.
| Square Miles (mi²) | Square Kilometers (km²) |
|---|---|
| 0.259 km² | |
| 0.6475 km² | |
| 1.295 km² | |
| 2.59 km² | |
| 3.885 km² | |
| 5.18 km² | |
| 6.475 km² | |
| 7.77 km² | |
| 12.95 km² | |
| 19.425 km² | |
| 25.9 km² | |
| 38.85 km² | |
| 51.8 km² | |
| 64.75 km² | |
| 129.5 km² | |
| 259 km² | |
| 647.5 km² | |
| 1295 km² |
Square Kilometers to Square Miles Conversion Table
| Square Kilometers (km²) | Square Miles (mi²) |
|---|---|
| 1 km² | 0.3861003861 mi² |
| 2 km² | 0.7722007722 mi² |
| 5 km² | 1.9305019305 mi² |
| 10 km² | 3.861003861 mi² |
| 20 km² | 7.722007722 mi² |
| 25 km² | 9.6525096525 mi² |
| 50 km² | 19.305019305 mi² |
| 100 km² | 38.61003861 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 in Everyday Objects
Common real-world examples that make Square Miles and Square Kilometers easy to picture at a glance.
| Square Miles (mi²) | Square Kilometers (km²) | |
|---|---|---|
| Manhattan land area | 22.8 mi² | 59.052 km² |
| Washington, DC land area | 61.4 mi² | 159.026 km² |
| Central Park | 1.31 mi² | 3.3929 km² |
| Gibraltar | 2.6 mi² | 6.734 km² |
| New York City land area | 302.6 mi² | 783.734 km² |
| The Isle of Man | 220.8494208494 mi² | 572 km² |
| Rhode Island land area | 1033.8 mi² | 2677.542 km² |
When You Need Square Miles to Square Kilometers Conversions
Comparing City Footprints
Chicago's 227.7 sq mi converts to 589.74 sq km for the Aussie reader wondering whether the Windy City sprawls more than home — it comes in at less than half the Brisbane City Council area (1,343 sq km).
Bushfire Incident Reporting
US incident commands size fires in square miles; a 5 sq mi burn is 12.95 sq km — about 1,295 hectares, the unit you'll see in NSW RFS and CFS incident alerts back home.
National Park Statistics
Yellowstone's 3,471 sq mi becomes about 8,990 sq km — less than half of Kakadu's 19,816 sq km — letting travel writers rank US parks against our own outback giants.
Shire and Council Sizing
A 320 sq mi shire — the sort of figure still lurking in older LGA records — converts to 828.8 sq km for grant applications that request service-area figures in metric units.
Related Area Conversions
How to Use
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1
Enter the Area in sq mi
Type the square-mile figure from your source — for example, 22.8 sq mi for Manhattan, or 512 sq mi for Uluru-Kata Tjuta as it appears in pre-metric Aussie tourism brochures
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2
See the Square Kilometres
The result appears instantly: 22.8 sq mi = 59.05 sq km — a shade bigger than Sydney Harbour — the metric figure local readers expect
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3
Copy or Reverse
Copy the figure into your assignment, article, or report, or hit Swap to turn a sq km statistic back into sq mi for a US audience
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4
Check the Table
Scan the table for anchors like 5 sq mi = 12.95 sq km and 500 sq mi = 1,295 sq km — the latter landing not far off Uluru-Kata Tjuta National Park (1,326 sq km)
Why Use Be Converter?
Instant Conversion
Get square miles in square kilometres in real time as you type — ideal for fact-checking US travel guides, bushfire coverage, or old land documents on the fly
Precision Guaranteed
Applies the exact 2.59 factor implied by the mile's 1.60934 km definition — no rounded textbook shortcuts, so your figures stack up against Geoscience Australia data
Handy Reference Table
Territory sizes at a glance — 1 sq mi = 2.59 sq km, 50 sq mi = 129.5 sq km, 500 sq mi = 1,295 sq km — so you can match US stats to places like Phillip Island or Uluru-Kata Tjuta National Park
Swap with One Click
Toggle back to sq km to sq mi instantly when you need to explain Kakadu's 19,816 sq km to a US reader in their own units
Free & Unlimited
No registration required. Convert every city, shire, station, and national park figure you research — always free
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Frequently Asked Questions
How many square kilometres are in 1 square mile?
How do I convert 5 square miles to sq km?
What is 100 sq mi in square kilometres?
Is a square mile bigger than a square kilometre?
Why do US geography statistics use square miles?
How many sq km is Manhattan?
How many sq km is 50 square miles?
How do I convert sq mi to sq km precisely?
About Our Square Miles to Square Kilometres Converter
Our free online square miles to square kilometres converter translates US land statistics into the metric units Aussies use every day. American city sizes, county areas, national parks, lakes, and wildfire perimeters all arrive in square miles, while everything at home — from ABS data to council plans and national park fact sheets — is quoted in square kilometres or hectares. It's also a lifesaver for pre-metric records: pastoral leases, mining tenements, and newspaper clippings from before Australia's 1970s conversion often quote square miles. Whether you're a student, journalist, or property researcher, this tool applies the exact factor of 2.59 sq km per sq mi to every figure you enter.
Expert Tips for sq mi to sq km Conversion
The 2.59 factor is a squared length ratio: 1.60934 km per mile, squared, gives 2.59 — so lengths convert by 1.60934 while areas convert by 2.59.
Memorise a few anchors: Manhattan 22.8 sq mi = 59.05 sq km, Chicago 227.7 sq mi = 589.74 sq km, and the ACT at 910 sq mi = 2,358 sq km — a handy yardstick for sizing US cities against the national capital.
For national parks, convert before comparing: Yellowstone at 3,471 sq mi is about 8,990 sq km — less than half the size of Kakadu (19,816 sq km), our biggest land park.
Mental shortcut: multiply sq mi by 2.6 — a 320 sq mi shire gives 832 sq km against the exact 828.8, close enough for a chat at the barbie.
Land vs total area matters in geography: US figures often exclude water (NYC land is 302.6 sq mi) while metric sources include it; always convert on the same basis or your comparisons drift.
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