Convert A.U. of Length (a.u.) to Foot (US Survey) (ft (US)) instantly.
About these units
A.U. of Length (a.u.)
The atomic unit of length, also known as the Bohr radius unit in atomic units, is approximately 5.29177 × 10⁻¹¹ meters. It is defined as the radius of the lowest-energy orbital of the hydrogen atom, providing a natural scale for describing atomic and quantum mechanical systems. Atomic units were devised to simplify equations in quantum chemistry and atomic physics by normalizing fundamental constants such as electron charge, Planck's constant, and electron mass to 1. In this system, many equations become dimensionless and far easier to manipulate mathematically. The atomic unit of length is essential in molecular orbital calculations, quantum simulations, and the study of electron behavior in atoms and molecules. Its use reflects an approach to physics in which units are chosen to match the natural scales of the systems being studied.
Foot (US Survey) (ft (US))
The US Survey Foot is a standardized version of the foot, defined as exactly 1200/3937 meters (~0.30480061 m). It was adopted to maintain continuity with older surveying records when converting to the metric system. Surveyors, engineers, and geographers in the United States used this unit for mapping, cadastral surveys, and infrastructure projects. Its slight difference from the international foot allows historical survey data to align accurately with modern geodetic coordinates. Although the international foot is now more common, the US survey foot remains relevant for interpreting historical survey data and legal property boundaries.