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Conversion Formula:
Convert Acre to Square Kilometer (ac to km²) instantly with accurate, readable results.
Convert between square meters, acres, square feet, hectares, and other common units with our Area Unit Converter. This intuitive unit conversion tool helps you calculate land size, floor space, and surface area across both metric and imperial systems. Whether you're working on real estate, construction, or geography tasks, our area unit conversion calculator ensures precise and instant results.
Acre (ac) - Imperial/US land area
Acre is a traditional unit of area used for land measurement in the UK, US, and other countries. Used in real estate, agriculture, and land records; metrically it converts exactly because the foot is defined in meters.
- Symbol: ac
- System: Imperial/US customary (non-SI, accepted for use with SI
- Exact relations: 1 acre = 43,560 ft² = 4,840 yd² = 160 square rods (perches/poles) = 10 square chains
- Metric equivalents (exact): 1 acre = 4046.8564224 m² ≈ 0.40468564224 ha
- Typical examples: suburban lots (fractions of an acre); farm fields of tens to hundreds of acres; sports complexes measured in multiple acres
Square kilometer (km²) - large SI unit of area
Square kilometer is an SI unit of area equal to the area of a square with sides of 1 kilometer. Used for city sizes, land cover, and geographic mapping.
- Symbol: km²
- System: SI derived unit
- Exact relations: 1 km² = (1000 m)² = 1,000,000 m² = 100 ha = 10⁸ dm² = 10¹⁰ cm² = 10¹² mm²
- Imperial/US equivalents: 1 km² ≈ 0.386102159 mi² ≈ 247.105381 acres
- Typical examples: municipality areas, national park extents, watershed and habitat mapping