Constants & Units · constant

Bohr magneton

μ_B = 9.274 010 0657(29) × 10⁻²⁴ J T⁻¹

Unit
J T⁻¹
Value
9.274 010 0657(29) × 10⁻²⁴
Exact
no
Note
The magnetic moment of one electron spin — the quantum of magnetism in matter.
Symbol
μ_B
Category
Atomic & nuclear
Numeric
9.2740100657e-24
Uncertainty
±3.1 × 10⁻¹⁰ relative

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From the Constants database in Notion, last edited 2026-08-15. This page is the row, rendered by the build; nothing on it is written by hand.