Convert Earth's Distance from Sun (AU (es)) to Chain (ch) instantly.
About these units
Earth's Distance from Sun (AU (es))
The average distance from the Earth to the Sun is approximately 1 astronomical unit (AU) = 149,597,870.7 km. This distance forms the basis for measuring interplanetary distances within the solar system. Astronomers rely on the AU to calculate orbital periods, planetary alignments, and the intensity of solar radiation at different planets. Its precise measurement comes from radar ranging to planets, spacecraft telemetry, and observations of orbital mechanics. The AU provides a human-scaled reference for the vast distances in the solar system, bridging Earth-based intuition with astronomical scales. It is a cornerstone unit in celestial mechanics and planetary science.
Chain (ch)
A chain is equal to 66 feet or 4 rods, and it was standardized by surveyor Edmund Gunter in the 17th century. "Gunter's chain," consisting of 100 metal links, became the backbone of land surveying in the English-speaking world for centuries. Its convenience stems from simple arithmetic: 10 square chains make an acre, making land area calculations straightforward. Railroads, farmland, and city parcels across the United States and the Commonwealth nations were once laid out using chains, so the unit appears in countless historical records. Even today, some legal property descriptions still reference chain-based measurements, making the unit relevant for modern surveyors who interpret old maps. Although high-precision digital equipment has replaced physical chains, the unit's structural role in land division ensures its lasting importance.