Electron magnetic moment anomaly = 1.159 652 180 46 × 10−3 (dimensionless)

Value
1.159 652 180 46 × 10−3
Unit
(dimensionless)
Uncertainty
0.000 000 000 18 × 10⁻³
Copy-ready
1.15965218046e-3

How far the magnetic moment of the electron departs from the Dirac value: a = (|g| − 2)/2.

One of the most precise comparisons between experiment and the Standard Model; a persistent disagreement would point to new particles.

NIST, Fundamental Physical Constants — Complete Listing (2022 CODATA adjustment), retrieved 2026-07-26.

Magnetic moments, g-factors and gyromagnetic ratios

Deuteron magnetic momentElectron magnetic momentElectron g factorElectron gyromagnetic ratioElectron magnetic moment anomalyHelion g factorHelion magnetic momentHelion shielding shiftMuon g factorMuon magnetic momentMuon magnetic moment anomalyNeutron magnetic momentNeutron g factorNeutron gyromagnetic ratioProton g factorProton gyromagnetic ratioProton magnetic momentProton magnetic shielding correctionShielded helion gyromagnetic ratioShielded helion magnetic momentShielded proton gyromagnetic ratioShielded proton magnetic momentShielding difference of d and p in HDShielding difference of t and p in HTTriton g factorTriton magnetic moment

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All physical constants

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