Square Millimeters to Pyeong (mm² to py)

1 square millimeter equals 3.025×10⁻⁷ pyeong exactly.

1 square millimeter = 3.025×10⁻⁷ pyeong

How to convert square millimeters to pyeong

To convert square millimeters to pyeong, multiply the number of square millimeters by 3.025×10⁻⁷. This factor is exact. To go the other way, multiply pyeong by 3,305,785.124 (rounded).

pyeong = square millimeters × 3.025×10⁻⁷

Example: 10 square millimeters = 0.000003025 pyeong.

About these units

Square Millimeter (mm²)

Metric (SI)Current unit

A square one millimeter on a side. Used for the cross-section of wires and small parts.

Gauss gets the credit for putting the millimeter at the base of a scientific measuring system. His 1832 proposal for absolute units used the millimeter, milligram and second, although the centimeter-based CGS system later won out among scientists. The square millimeter is a one-thousandth-by-one-thousandth square of a meter, so it takes a million of them to make a square meter, and it has no famous inventor of its own.

Electricians know it best. Wire and cable sizes are given as the cross-sectional area of the copper conductor, and the standard sizes listed for UK domestic wiring are 1, 1.5, 2.5, 4, 6 and 10 mm². Twin and earth cable of 2.5 mm² typically serves sockets on a 16 A radial or 32 A ring circuit, 1 mm² serves lighting on a 6 A breaker, and 4 mm² feeds a cooker or shower. Conductor size depends on current capacity and allowed voltage drop, not on voltage alone. One square inch is exactly 645.16 mm², so small parts in either system compare easily.

1 square millimeter = 0.000001 square meters (exactly).

Sources: Wikipedia: Electrical wiring in the United Kingdom; Wikipedia: Centimetre-gram-second system of units; Wikipedia: Square metre

Pyeong (py)

KoreanTraditional unit (still used in some regions)

Exactly 400/121 m² (3.3058 m²), the Korean unit equivalent to the Japanese tsubo and the Taiwanese ping. Still used informally for apartment sizes in Korea and Taiwan.

Floor space in South Korea is still often quoted in pyeong, a word that, like the Japanese tsubo and Taiwanese ping, stands for a square whose side is one kan or bu, equal to 36 square Chinese or Japanese feet. The Korean version was fixed during the Japanese occupation at 400/121 square meters, about 3.3058 square meters, which is roughly the area of two tatami mats.

Korean sources use the pyeong as the standard traditional measure for homes. Typical benchmarks are about 25 pyeong for an average house and 8 to 12 for a studio flat. Official use was banned in 1961, but the ban had little effect until commercial use was criminalised from 1 July 2007, after which listings show square meters with the pyeong figure as an informal extra. Taiwan introduced the ping under Japanese rule and still uses it, at about 3.305 square meters. Wikipedia notes that a Chinese version based on metric feet would be near 4 square meters but is almost unknown.

1 pyeong = 3.305785124 square meters (approximately).

Sources: Wikipedia: Pyeong

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