Bohr Magneton

The natural unit of magnetic moment for an electron, produced by its charge, spin, and mass.

Specifications & Metrics

symbol

μ_B

status

Measured (CODATA 2022)

value

9.2740100657 × 10⁻²⁴ ± 2.9 × 10⁻³³ J·T⁻¹

Relative Scale in Constants

Core Principles & Analysis

• Equals eħ/2mₑ — the magnetic moment a Bohr-model electron orbit would produce.
• The electron's actual moment is 1.00116 μ_B; predicting that anomaly is QED's most precise triumph.
• Sets the scale of Zeeman line splitting and of an electron beam's deflection in a Stern-Gerlach magnet.

Open in the Simulator — run this concept live