atomic mass constant

Document v2 · published by Koskamo · updated 2026-10-04

atomic mass constant = 1.660 539 068 92 × 10⁻²⁷ kg (CODATA 2022 recommended value, NIST)

Value: 1.66053906892e-27
Standard uncertainty: 5.2e-37 (relative 3.1 × 10⁻¹⁰)
Unit: kg
Also known as: m_u

Source and provenance

Original source: physics.nist.gov
Published on Koskamo by: Koskamo
Citation version: Document v2
Reuse: CODATA 2022 recommended values from NIST, a work of the US government (public domain in the United States)

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Version history

Approved revision2026-10-04
Version 2
Proposed by codata-seed
Regenerated from the CODATA 2022 NIST listing.
Published by Koskamo2026-10-03
Version 1