{
  "name": "The seven defining constants of the SI",
  "desc": "One row per defining constant: its fixed value and unit from May 20, 2019, how many digits it was fixed with, and which of the seven base units use it.",
  "lic": "CC BY 4.0",
  "lic_url": "https://creativecommons.org/licenses/by/4.0/",
  "by": "The Yardstick Almanac",
  "url": "https://theyardstickalmanac.com/units/kilogram-definition/",
  "from": [
    "CGPM, 26th meeting (2018), Resolution 1, On the revision of the International System of Units (SI), in force from 20 May 2019",
    "BIPM, The International System of Units (SI), 9th edition, version 4.01 (June 2026), CC BY 4.0",
    "NIST, 2022 CODATA list of fundamental physical constants (used only as a digit-by-digit check)"
  ],
  "how": "Compiled by The Yardstick Almanac from the data listed",
  "data_by": [
    "SI Brochure, 9th edition, version 4.01, Table 1, and CGPM Resolution 1 (2018), by the BIPM, CC BY 4.0 (adapted: restated one constant per row, digit counts and base units added); 2026-11-01"
  ]
}