Square metric area unit.
Square Kilometers to Ares Converter — km2 to a
Convert Square Kilometer (km2) to Are (a) using the exact conversion factor (1 square kilometer = 10,000 are). See the formula, worked examples, conversion table, history, and common uses.
Square Kilometers to Ares converter
Converter
Area Converter
Convert land, construction, mapping, survey, and scientific area units.
Context values
Some unit families need one extra value for a physically accurate result.
An are is 100 square meters.
Result = input x 1e+6 / 100.
Area uses the square meter as the base unit.
Reserved above the conversion cards and below the converter.
About Converting Square Kilometers to Ares
Comparing Square Kilometer and Are is common in agriculture and real estate, where US land is typically measured in acres and most of the rest of the world uses hectares. Square Kilometer is most often used for national and regional land-area statistics.
Formula
ares = square kilometers × 10000
This factor comes from each unit's defined relationship to the category's base unit: 1 square kilometer equals 1000000 base units, and 1 are equals 100 base units, so dividing one by the other gives the direct square kilometer-to-are factor of 10000.
Simple example
1 km2 × 10000 = 10,000 a
1 square kilometer = 10,000 ares.
Real-world example
10 km2 × 10000 = 100,000 a
10 square kilometers = 100,000 ares.
Conversion table
| Square Kilometer (km2) | Are (a) |
|---|---|
| 1 km2 | 10,000 a |
| 5 km2 | 50,000 a |
| 10 km2 | 100,000 a |
| 25 km2 | 250,000 a |
| 50 km2 | 500,000 a |
| 100 km2 | 1,000,000 a |
Reverse conversion: Are to Square Kilometer
1 a × 0.0001 = 0.0001 km2
1 are = 0.0001 square kilometers.
square kilometers = ares × 0.0001
For a page dedicated to this direction, see Are to Square Kilometer.
Understanding the Square Kilometer
Square Kilometer (km2) measures area. A square kilometer is one million square meters — the area of a 1 km × 1 km square. It is classified as a SI derived (metric prefix) unit.
Where it's used: Used worldwide for city, region, and country-scale area reporting.
Uses of the Square Kilometer today
- National and regional land-area statistics
- City and urban planning at large scale
- Geography and cartography
History of the Square Kilometer
Like other metric-prefixed area units, the square kilometer follows automatically from the kilometer once the meter was standardized in the 1790s French metric reform.
Historical origin. Square Kilometer was not the invention of a single named person; it developed through the process described above.
Understanding the Are (a)
An are is 100 square meters.
Square Kilometer — sources
- BIPM SI Brochure — Coherent derived units — Basis for metric-prefixed area units.
Reserved between the cards and the FAQ so the page stays balanced.
Frequently asked questions
How many ares are in 1 square kilometer?
1 square kilometer equals 10,000 ares, using the exact defined conversion factor rather than an estimate.
How do I convert square kilometer to are?
Multiply the square kilometer value by 10000. The converter above does this instantly to whatever precision you set.
How do I convert are back to square kilometer?
Use the reverse factor: 1 are equals 0.0001 square kilometers. You can also use the swap control in the converter above to flip the direction instantly.
What is a square kilometer?
Square Kilometer (km2) measures area. A square kilometer is one million square meters — the area of a 1 km × 1 km square. It is classified as a SI derived (metric prefix) unit.
What is a are?
Are (a) is a unit of area.
Is the square kilometer to are conversion exact?
Yes. Both square kilometer and are are defined by fixed standards rather than physical artifacts, so the factor of 10000 used above is exact to as many digits as you choose to display.
Where is the square kilometer still used today?
Used worldwide for city, region, and country-scale area reporting.