# Bohr radius conversions

The Bohr radius conversion selector here selects the length/distance measurement unit to convert to starting from Bohr radius (a0). To make a conversion starting from a unit of length other than Bohr radius, simply click on the "Reset" button.

## About Bohr radius

The **Bohr radius** is a unit of length in atomic units. The Bohr radius expresses the most likely position of the electron in a hydrogen atom, the simplest atom, in its ground state (the Bohr model of an atom).

The Bohr radius unit is named after the Danish physicist Niels Henrik David Bohr (1885 - 1962), who made fundamental contributions to understanding the atomic structure and quantum mechanics.

The Bohr radius of hydrogen has a value of approximately 5.3 × 10^{-11} meters (a_{0} ≈ 5.3 × 10^{-11} m), the base unit of length in the International System of Units (SI).

The Bohr radius (a_{0}) is also equal to approximately 0.53 angstroms (Å) (a non-SI unit of length), or 5.3 × 10^{-5} micrometers (μm), or 5.3 × 10^{-8} millimeters (mm) or 5.3 × 10^{-9} centimeters (cm), which are SI units of length.

The Bohr radius is used in atomic physics calculations.

Symbol: a_{0}

Plural: Bohr radii