What is Area Conversion?
Convert square meters, hectares, acres, and more.
Supported units: Square Meter (m²), Square Kilometer (km²), Square Centimeter (cm²), Hectare (ha), Acre (ac).
From one day's ploughing to the square metre
Area units are deeply rooted in farming history. The acre (≈ 4,047 m²) was originally the amount of land a man with one ox could plough in a day — tall, narrow strips that match medieval field layouts. The hectare (10,000 m² = 100 m × 100 m) was introduced with the metric system and remains the standard for agriculture and land registries across Europe, Asia, and South America. In East Asia, traditional units still dominate real estate: Taiwan uses the 甲 (≈ 0.9699 hectares, inherited from 17th-century Dutch surveying) and the 坪 (3.306 m², originally 36 square shaku, a human-scale room measurement). Japan uses 坪 identically; Korea uses 평 (pyeong) with the same value. When you see a Tokyo apartment listed at "20坪" that's 66 m², and a Taiwanese condo at "30 坪" is 99 m² — knowing the conversion is the difference between a fair deal and getting fooled.
Where you run into area conversions
Real estate
Property listings vary wildly by country: square feet (US/UK), square metres (most of Europe/Asia), 坪 (Japan, Taiwan, Korea), 甲 (Taiwan rural land). Comparing two listings across borders requires converting units and knowing what the price-per-unit actually buys.
Agriculture
Farms worldwide report area in hectares or acres depending on country. US farmland at "$5,000/acre" is about $12,350/hectare — essential arithmetic for any international land transaction or yield comparison.
Flooring, paint, and materials
Paint labels state coverage in m² per litre (or ft² per gallon in the US); flooring is sold by m² or by ft². Getting this right prevents buying 20 % too little paint or one extra box of tiles.
Maps and urban planning
City sizes are quoted in km² (world) or mi² (US). Comparing a 120 km² city to a 60 mi² one needs a factor of 2.59 — easy to misread without the conversion.
East Asian traditional units
Anyone researching property, farmland, or family land records in Taiwan, Japan, or Korea must convert 坪/平/평 to m² and 甲 or 反 to hectares. Local documents sometimes mix both.
Common Conversions
- 1 Square Meter (m²) = 0.000001 Square Kilometer (km²)
- 1 Square Meter (m²) = 10000 Square Centimeter (cm²)
- 1 Square Kilometer (km²) = 1000000 Square Meter (m²)
- 1 Square Kilometer (km²) = 1.0000e+10 Square Centimeter (cm²)
- 1 Square Centimeter (cm²) = 0.0001 Square Meter (m²)
- 1 Square Centimeter (cm²) = 1.0000e-10 Square Kilometer (km²)
FAQ
Q: How many square meters in 1 hectare?
A: 1 hectare = 10,000 square meters.
Q: How to convert acres to square meters?
A: Multiply by 4046.86. Example: 1 acre ≈ 4046.86 m².
Q: How many square kilometers in 1 square meter?
A: 1 m² = 0.000001 km².
Q: How big is 1 坪 (ping/tsubo)?
A: 1 坪 = 3.306 m² (roughly the size of two tatami mats or a small bathroom). Taiwan, Japan and Korea use the same value, though in Korea it's written 평 (pyeong). A 30-坪 apartment is 99 m² or about 1,070 sq ft.
Q: Why does an acre equal 43,560 square feet — such an odd number?
A: An acre was historically 1 furlong long by 1 chain wide (660 ft × 66 ft). Both units came from medieval English agriculture and eventually got standardised in the metric world as 4,046.856 m². The odd number is a survival of that measurement system, not a modern choice.