Convert Fingerbreadth (fingerbreadth) to Bohr Radius (a₀) instantly.
About these units
Fingerbreadth (fingerbreadth)
The fingerbreadth, approximately 1.9–2 cm, is the width of an average adult finger and represents one of the smallest practical body-based units. It was historically used for fine measurement in weaving, tailoring, and small-scale construction, complementing units like cubits and handbreadths. Its human-scale precision made it intuitive, particularly in societies without standardized rulers or measuring rods. Fingerbreadths continue to be referenced in scholarly studies of ancient measurements, providing insight into the practical and anthropometric foundations of early systems.
Bohr Radius (a₀)
The Bohr radius, equal to approximately 5.29177 × 10⁻¹¹ meters, is the most probable distance between the electron and nucleus in the ground state of hydrogen according to the Bohr model. While modern quantum mechanics has evolved far beyond the Bohr model, the radius remains a remarkably accurate approximation for average atomic dimensions. The Bohr radius acts as a natural "yardstick" for the size of atoms and is frequently used in atomic physics and quantum chemistry. Many atomic properties — orbital sizes, electron probability distributions, and energy levels — are conveniently expressed in multiples of the Bohr radius. Because it reflects fundamental constants, including Planck's constant and the electron charge, the Bohr radius also appears in theoretical analyses of physical systems and helps unify atomic physics concepts across different contexts.