{
  "url": "https://openlegislation.uk/weights-and-measures-act-1985/schedule-1/part-I/crossheading-metric-units",
  "json_url": "https://openlegislation.uk/weights-and-measures-act-1985/schedule-1/part-I/crossheading-metric-units.json",
  "legislation": "ukpga/1985/72",
  "legislation_title": "Weights and Measures Act 1985",
  "legislation_url": "https://openlegislation.uk/weights-and-measures-act-1985",
  "path": "schedule/1/part/I/crossheading/metric-units",
  "kind": "crossheading",
  "number": null,
  "heading": "Metric units",
  "text": "Kilometre =\n1000 metres.\nMETRE\nfor which the symbol “m” is used, is the SI unit of length, defined by taking the fixed numerical value of the speed of light in vacuum c to be 299 792 458 when expressed in the unit m/s, where the second is defined by taking the fixed numerical value of the caesium frequency ΔvCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s-1.\nDecimetre =\n1/10 metre.\nCentimetre =\n1/100 metre.\nMillimetre =\n1/1000 metre.",
  "extent": null,
  "status": null,
  "version": "current",
  "annotations": [
    {
      "type": "F",
      "label": "F1",
      "text": "Words in Sch. 1 Pt. 1 substituted (13.6.2020) by The Weights and Measures Act 1985 (Definitions of Metre and Kilogram) (Amendment) Order 2020 (S.I. 2020/586), arts. 1(b), 2(2)"
    }
  ],
  "outstanding_effects": [
    {
      "type": "omitted",
      "affecting": "ukpga/2025/20",
      "affecting_title": "Product Regulation and Metrology Act 2025"
    }
  ],
  "provenance": {
    "source": "legislation.gov.uk",
    "source_url": "https://www.legislation.gov.uk/ukpga/1985/72/schedule/1/part/I/crossheading/metric-units",
    "retrieved_at": "2026-10-29T09:59:41.980135+00:00"
  },
  "licence": "Open Government Licence v3.0",
  "licence_url": "https://www.nationalarchives.gov.uk/doc/open-government-licence/version/3/",
  "attribution": "Contains public sector information licensed under the Open Government Licence v3.0. Source: legislation.gov.uk, The National Archives."
}