How to use the converter
- Choose Area or Length at the top.
- Type a number into any unit, for example 30 in Ping, and every other unit updates immediately.
- Or tap a common conversion such as “1 mu → acres” to fill it in.
- Press Copy results to copy all units as text.
What are mu, ping and jia?
Mu (亩) is the traditional Chinese land unit still widely used for farmland in mainland China: 15 mu make one hectare, so 1 mu ≈ 666.67 m² ≈ 0.165 acre. Ping (坪) is used for property sizes in Taiwan: one ping is a square of 6 Taiwanese chi per side, exactly 400/121 m² ≈ 3.306 m² ≈ 35.58 sq ft. Jia (甲) is Taiwan’s farmland unit: 1 jia = 2,934 ping ≈ 0.97 hectare.
Common area conversions
| Unit | Square meters | Square feet | Acres |
|---|---|---|---|
| 1 ping | 3.3058 | 35.58 | 0.000817 |
| 1 mu (China) | 666.67 | 7,175.9 | 0.1647 |
| 1 jia (Taiwan) | 9,699.17 | 104,401 | 2.397 |
| 1 hectare | 10,000 | 107,639 | 2.471 |
| 1 acre | 4,046.86 | 43,560 | 1 |
Two different “mu”
Mainland China’s mu (shi mu) is about 666.67 m². Old Taiwanese records sometimes use a mu borrowed from the Japanese system, equal to 30 ping or about 99.17 m², nearly seven times smaller. Use the Chinese mu for mainland land data, and jia, fen and ping for Taiwan.
From nanometers to light-years
Each metric step down is a thousand times smaller: a millimeter is 1,000 micrometers, a micrometer is 1,000 nanometers, and so on to picometers and femtometers. A human hair is about 70 micrometers wide, a virus about 100 nanometers, an atom about 100 picometers (one ångström), and an atomic nucleus only a few femtometers. The Planck length, about 1.6×10⁻³⁵ m, is considered the smallest meaningful length in physics. At the other end, astronomers use the astronomical unit (Earth to Sun, about 150 million km), the light-year (about 9.46 trillion km) and the parsec (about 3.26 light-years). Very large or small results are shown as “×10ⁿ”, and you can type numbers like 1e-9 too.