What it does
NIST provides fundamental-constant values and related reference material on units, conversion factors and measurement uncertainty.
Check the adjustment associated with a constant before recording its value. The reference links constants with SI and uncertainty guidance, which matters when a calculation requires more than a rounded textbook number. Preserve the value's stated context and source in your notes.
The linked values are identified with the 2022 CODATA adjustment in this source. Preserve that adjustment, unit and uncertainty when a calculation needs reproducible precision.
Sources
- Fundamental Physical Constants | NIST (Oct 26, 2026)