Proton gyromagnetic ratio = 2.675 221 8708 × 10⁸ s⁻¹·T⁻¹

Name: Proton gyromagnetic ratio — CODATA 2022 value
Creator: NIST

Value: 2.675 221 8708 × 10⁸
Unit: s⁻¹·T⁻¹
Uncertainty: 0.000 000 0011 × 10⁸
Copy-ready: 2.6752218708e8

Gyromagnetic ratio of the proton: its magnetic moment divided by its spin angular momentum.

Multiplied by a magnetic field it gives the precession (Larmor) frequency — the frequency NMR and MRI machines tune to. The MHz/T form beneath is the one scanner engineers use.

The same quantity, other ways NIST lists it

Quantity (NIST name)	Value	Unit	Uncertainty
Proton gyromagnetic ratio in MHz/T	42.577 478 461	MHz·T⁻¹	0.000 000 018

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

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The same quantity, other ways NIST lists it

Magnetic moments, g-factors and gyromagnetic ratios

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All physical constants