Convert Square Kilometer to Acre
Convert square kilometers to acres instantly. 1 square kilometer = 247.1053814672 acre — use the live calculator, the exact formula, a conversion table and worked examples. Also check the Acre to Square Kilometer converter for the reverse conversion.
Units explained
Square Kilometer
A square kilometer is a metric unit of area equal to 1,000,000 m² (one million square meters), or 100 hectares. It is used for measuring large land areas, regional geography, and country-scale statistics.
Derived by squaring the kilometer (1000 m). The kilo- prefix comes from the Greek 'chilioi' (thousand).
Square kilometers express the area of cities, districts, lakes, forests, and entire countries. India's total area is approximately 3,287,263 km². 1 km² equals 100 hectares or about 247.105 acres.
Kilometer has been part of the metric system since 1795.
Acre
An acre is an imperial unit of area equal to exactly 4046.8564224 m². It is the most widely used non-metric unit for land area, particularly in the US, UK, and India.
Originally defined in medieval England as the area one yoke of oxen could plow in a day, approximately 40 perches by 4 perches. Standardized via the 1959 International Yard and Pound Agreement.
Acres are the standard land measurement unit in the US (real estate, agriculture), the UK (rural property), and widely used in India (alongside hectares and traditional regional units). 1 acre = 4840 sq yd = 43,560 sq ft = 0.4047 hectare.
Medieval English farming origin; modern exact value standardized in 1959.
Square Kilometer to Acre conversion formula
The relationship between square kilometers and acres:
To convert square kilometers to acres, multiply the value in square kilometers by 247.1053814672. To reverse, multiply acres by 0.0040468564.
How to use this converter
Type a value into the calculator. The result in acres updates as you type. Tap a quick value, copy the result with one click, or use the swap arrow to jump straight to the Acre to Square Kilometer converter for the reverse direction.
Step-by-step: convert square kilometers to acres
- Write down the value in square kilometers (km²).
- Multiply that value by the factor 247.1053814672.
- The product is the equivalent value in acres (ac).
- To reverse, multiply the acre value by 0.0040468564.
Worked examples
Example 1 — Convert 1 km² to ac:
1 × 247.1053814672 = 247.1053814672 ac
Example 2 — Convert 100 km² to ac:
100 × 247.1053814672 = 24710.5381467165 ac
Square Kilometer to Acre conversion table
Standard reference values for converting square kilometers to acres:
| Square Kilometer [km²] | Acre [ac] |
|---|---|
| 0.01 | 2.4710538147 |
| 0.1 | 24.7105381467 |
| 1 | 247.1053814672 |
| 2 | 494.2107629343 |
| 3 | 741.3161444015 |
| 4 | 988.4215258687 |
| 5 | 1235.5269073358 |
| 10 | 2471.0538146717 |
| 20 | 4942.1076293433 |
| 30 | 7413.161444015 |
| 40 | 9884.2152586866 |
| 50 | 12355.2690733583 |
| 100 | 24710.5381467165 |
| 500 | 123552.6907335827 |
| 1000 | 247105.3814671653 |
Frequently asked questions
How many acres is 1 square kilometer?
How do I convert square kilometers to acres?
How do I convert acres back to square kilometers?
How many acres is 100 square kilometers?
Popular area unit conversions
Convert Square Kilometer to other area units
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Metric / SI (15 units)
Imperial / US Customary (15 units)
US Survey (5 units)
Indian Subcontinent (16 units)
Other Regional (10 units)
Scientific / Physics (5 units)
Sources & references
Conversion factor (1 km² = 247.1053814672 ac) verified against the following authoritative sources:
- BIPM — The International System of Units (SI Brochure 9th ed.)
Official BIPM publication defining the seven SI base units (including the meter) and the rules for their use. The global authority on units of measurement.
- NIST — Guide to the SI
US National Institute of Standards and Technology reference covering the SI base and derived units with definitions and usage rules for US technical practice.
- NIST Special Publication 811 — Guide for the Use of the International System of Units
Detailed NIST guide covering exact conversion factors between SI and US customary units along with formatting and rounding conventions.
- NIST — Refinement of values for the yard and pound (Federal Register 1959)
The treaty (signed by US
- International Hydrographic Organization — Resolution on the Nautical Mile
International authority that standardised the nautical mile at exactly 1852 m in 1929 — the value adopted worldwide for sea and air navigation.