19 units across 4 measurement systems — metric, imperial, Chinese & Japanese
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| Unit | Symbol | System | 1 Unit = (in m²) |
|---|---|---|---|
| Square Kilometre | km² | Metric (SI) | 1,000,000 |
| Hectare | ha | Metric | 10,000 |
| Are | a | Metric | 100 |
| Square Metre | m² | Metric (SI base) | 1 |
| Square Centimetre | cm² | Metric | 0.0001 |
| 顷 (Qing) | 顷 | Chinese Traditional | 66,666.67 (100 mu) |
| 亩 (Mu) | 市亩 | Chinese Traditional | 666.667 |
| 分 (Fen) | 市分 | Chinese Traditional | 66.667 |
| 厘 (Li) | 市厘 | Chinese Traditional | 6.667 |
| 甲 (Chia) | 甲 | Taiwanese | 9,699 |
| 坪 (Tsubo / Ping) | 坪 | Japanese / Taiwanese | 3.3058 (2 tatami mats) |
| 畝 (Se) | 畝 | Japanese | 99.174 (30 tsubo) |
| Square Mile | mi² | Imperial / US | 2,589,988 |
| Acre | ac | Imperial / US | 4,046.86 |
| Square Yard | yd² | Imperial / US | 0.836127 |
| Square Foot | ft² | Imperial / US | 0.092903 |
| Square Inch | in² | Imperial / US | 0.00064516 |
The mu (市亩) is the standard unit of land area in China, used for everything from farm sizes to apartment block footprints. 1 mu = 666.667 m² = 1/15 hectare. This means 15 mu make exactly one hectare — a deliberate choice made in 1930 to align the traditional Chinese land system with the metric system. Before 1930, the "old mu" (旧亩) measured 614.4 m² — about 8.5% smaller. The reason: the old mu was derived from traditional length units based on the chi (尺), and when the chi was redefined against the meter, the mu changed with it. Today, when Chinese farmers talk about their "10 mu of rice paddies," they mean 6,667 m² — about two-thirds of a hectare, or 1.65 acres.
The Qing (顷) = 100 mu = 6.667 hectares. It's the large-scale land unit, used for farms, forests, and development zones. The Fen (分) = 0.1 mu = 66.667 m², and the Li (厘) = 0.01 mu = 6.667 m² are used for small plots and gardens. The entire system is decimal: 1 qing = 100 mu = 1,000 fen = 10,000 li. This makes Chinese land division far more logically structured than the imperial system's 640 acres per square mile.
1 tsubo (坪) = 3.3058 m² = 35.58 sq ft. In Japan and Taiwan, room sizes are measured in tsubo, not square meters or square feet. A tsubo is the area of two standard tatami mats (each 90 cm × 180 cm) placed side by side — a deeply intuitive visual reference. A typical Tokyo studio apartment is about 20 tsubo (66 m², or ~710 sq ft). A suburban house might be 40-50 tsubo. The Chia (甲) is the large land unit in Taiwan: 1 chia = 2,934 tsubo = 9,699 m² ≈ 0.97 hectares. Taiwan's farmland is bought and sold in chia — it's close enough to a hectare that rough comparisons work, but precise enough that real estate contracts specify the exact figure.
The acre has a wonderfully concrete origin: it was the amount of land a yoke of oxen could plow in one day — roughly 4,047 m², standardized as 43,560 square feet. The hectare (100 m × 100 m = 10,000 m²) was invented during the French Revolution as part of the metric system, designed to be clean, decimal, and universal. Today, the world is split: the US uses acres, most of the world uses hectares, China uses mu, and Japan/Taiwan use tsubo. If you're comparing international real estate listings, you need all four.
| From | To | Multiply By | Example |
|---|---|---|---|
| Acres | Hectares | × 0.404686 | 10 ac = 4.047 ha |
| Hectares | Acres | × 2.47105 | 5 ha = 12.36 ac |
| Mu | Hectares | ÷ 15 | 15 mu = 1 ha exactly |
| Mu | Acres | × 0.1647 | 100 mu = 16.47 ac |
| Mu | Square Metres | × 666.667 | 3 mu = 2,000 m² |
| Tsubo | Square Metres | × 3.3058 | 30坪 = 99.17 m² |
| Tsubo | Square Feet | × 35.583 | 20坪 = 711.7 ft² |
| Chia (甲) | Hectares | × 0.9699 | 5甲 = 4.85 ha |
| Chia (甲) | Mu | × 14.55 | 1甲 = 14.55 mu |
| Square Feet | Square Metres | × 0.092903 | 1,000 ft² = 92.9 m² |
| Square Miles | Acres | × 640 | 1 mi² = 640 ac |
| Hectares | Mu | × 15 | 10 ha = 150 mu |
Enter your value in the Acre field. The Hectare field updates instantly. 1 acre = 0.404686 hectares (about 0.4 ha). Quick reference: 10 acres ≈ 4 ha. A standard American football field (including end zones) is about 1.32 acres = 0.535 ha.
1 mu (市亩) = 666.667 m² = 0.0667 ha = 0.1647 acres. The simplest conversion: 15 mu = 1 hectare exactly. So divide mu by 15 to get hectares, or multiply by 0.1647 to get acres. Example: 100 mu = 6.67 ha = 16.47 acres — roughly the size of 12 football fields.
1 tsubo (坪) = 3.306 m² = 35.58 sq ft. It's defined as the area of two standard Japanese tatami mats side by side (each tatami is ~90 cm × 180 cm). In Japan and Taiwan, real estate listings quote floor area in tsubo, not square meters. A typical one-bedroom Tokyo apartment is about 20 tsubo (66 m² or ~710 sq ft). A 30-tsubo apartment is considered spacious for a couple.
1 chia (甲) = 2,934 tsubo = 9,699 m² = 0.9699 hectares = 2.397 acres. The chia is the primary unit for agricultural land in Taiwan. It's very close to one hectare (just 3% smaller), which makes rough comparisons easy. For context: a typical Taiwanese rice farm might be 2-5 chia. 1 chia = 14.55 Chinese mu.
The mu was redefined in 1930 to align with the metric system. The old mu (1915 standard, 旧亩) = 614.4 m², derived from traditional chi-based measurements. The modern mu (市亩) = 666.667 m² = 1/15 hectare. This roughly 8.5% size increase means historical Chinese land records before 1930 refer to a slightly smaller mu. This converter uses the modern standard — the version in active use across China today.