Convert Centimeter (cm) to A.U. of Length (a.u.) instantly.
About these units
Centimeter (cm)
The centimeter, 1/100 of a meter, strikes a balance between precision and ease of communication, making it indispensable in everyday life. Its size is well-matched to human-scale objects—furniture, body dimensions, school supplies, and clothing—so people in metric countries regularly estimate or visualize lengths in centimeters without tools. Many professions rely heavily on centimeters, including medicine (wound sizes, tumor dimensions), tailoring, building trades, and interior design. In science, centimeters serve as a practical unit for measurements too small for meters but too large for millimeters. Biologists, for example, may measure specimen sizes or growth stages in centimeters. Its intuitive scale and decimal alignment with meters ensure that both laypeople and professionals can convert easily among related 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.