Area unit conversion
Real-estate and mapping searches often mix metric and imperial area units.
Unit converter
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| From | To | Multiply by |
|---|---|---|
| 1 square meter (m²) | square centimeters (cm²) | 10000 |
| 1 square meter (m²) | square feet (ft²) | 10.7639 |
| 1 square foot (ft²) | square meters (m²) | 0.092903 |
| 1 square kilometer (km²) | square meters (m²) | 1e6 |
| 1 hectare (ha) | square meters (m²) | 10000 |
| 1 hectare (ha) | acres | 2.47105 |
| 1 acre | square meters (m²) | 4046.86 |
| 1 acre | square feet (ft²) | 43560 |
| 1 square mile (mi²) | acres | 640 |
| 1 square mile (mi²) | square kilometers (km²) | 2.58999 |
| 1 mu (亩, CN) | square meters (m²) | 666.667 |
| 1 ping (坪, TW/JP) | square meters (m²) | ≈3.306 |
Notes
- Chinese mu and Japanese/Taiwanese ping are traditional units — confirm local definition if legal docs matter.
- 1 hectare = 10,000 m² exactly.
How area conversion works: square the linear factor
To convert area units, square the linear factor — 1 ft² ≈ 0.092903 m², not 0.3048 m².
Every area unit is a length unit squared, and that fact drives the entire table. When you scale a length, its area scales by the square, so linear factors must be squared for areas. The sheet gives 1 foot = 0.3048 m; squaring it yields 1 square foot ≈ 0.092903 m², and going the other way 1 m² ≈ 10.7639 ft². The same rule explains why 1 square mile = 2.58999 km². Inside the metric system each linear step is a factor of 10, so each area step is a factor of 100 — hence 1 m² = 10,000 cm² and 1 km² = 1e6 m². And because an area scale has a true zero, converting between units is pure multiplication, with no offsets to remember.
Common mistakes when converting area units
One hectare equals exactly 10,000 m², or about 2.47105 acres.
By far the most common mistake is using the length factor instead of its square: converting ft² to m² with 0.3048 instead of 0.092903 overstates the area by roughly 10.76×, which quietly ruins floor plans and material estimates. Hectares and acres are also routinely swapped — 1 ha = 10,000 m² = 2.47105 acres, so a hectare is the larger unit; mixing them up misstates farmland by nearly two and a half times. Do not assume an acre is metric: it is exactly 43,560 ft², about 4046.86 m². Watch scientific notation too — the row "1 km² = 1e6 m²" means one million, not 100,000. Finally, remember that 640 acres per square mile is exact: it comes from the definition of the section in the US Public Land Survey, not from a rounded approximation.
Practical reference points for area units
One ping (坪) equals approximately 3.306 m² — a 10-ping room is about 33 m².
Numbers stick when you attach them to familiar objects. A full-size football or soccer pitch runs close to 0.7 hectares, which makes hectare estimates for fields feel intuitive. For farmland listings, keep the pairing 1 hectare ≈ 2.47105 acres in mind — many international land adverts quote both. For apartment floor plans, 1 m² ≈ 10.7639 ft² lets you sanity-check a 50 m² flat as roughly 538 sq ft. In Taiwan and Japan, rooms are quoted in ping (坪): one ping ≈ 3.306 m², so a "10-ping" bedroom is about 33 m². Mainland Chinese agriculture uses the mu: 1 mu = 666.667 m², and 15 mu ≈ 1 hectare — a handy mental shortcut when reading news about Chinese crop output or land transfers.
Regional and legal differences in area units
For cross-border contracts, state the exact conversion factor; table values are rounded for everyday use.
Context determines which units are official. The hectare — literally "hecto-are", 100 ares — is the legal metric land unit almost worldwide, yet it is not used in the United States, where land is measured in acres and square miles and the 640-acre section remains the backbone of the Public Land Survey System. The UK keeps acres as an informal but standard unit for land and estates. Taiwan quotes housing in ping (坪), while mainland China uses square meters for property and the mu in agriculture. Japan uses ping for room sizes and hectares for registry data. When contracts, tax records, or survey documents cross borders, convert to the locally recognized unit and state the exact factor used — the figures in the table above are rounded for convenience, not for legal work.
Frequently asked questions
- How big is one acre in square meters?
- One acre ≈ 4046.86 m², which is exactly 43,560 square feet.
- How many square meters are in a hectare?
- One hectare equals exactly 10,000 m², about 2.471 acres.
- How many square feet are in a square meter?
- One square meter ≈ 10.7639 sq ft; conversely, 1 sq ft ≈ 0.0929 m².
One acre equals exactly 4,046.856 square meters (or 43,560 square feet).