capitalization: SI/metric units

When writing the names of SI/metric units in full, capitalize only the word Celsius.

Symbols for units

When using symbols, capitalize the 19 symbols based on personal names and the letter L for litre.

  • 20 A (amperes, named after André-Marie Ampère)
  • 273.16 K (kelvins, named after Lord Kelvin)
  • 4.5 T (teslas, named after Nikola Tesla)
  • 12 V (volts, named after Alessandro Volta)
  • 30 L (litres)

All the other symbols remain in lower case.

  • 2 m (metres)
  • 475 g (grams)

Symbols for prefixes

Capitalize the symbols for the prefixes from mega to yotta.

  • M (mega)
  • G (giga)
  • T (tera)
  • P (peta)
  • E (exa)
  • Z (zetta)
  • Y (yotta)

The symbols for the other prefixes remain in lower case. Consistency is important here because the letters m and p are both used in symbols for two different prefixes:

  • mg (milligram); Mg (megagram)
  • pm (picometre); Pm (petametre)

See also abbreviations: International System of Units (SI).

Search by related themes

Want to learn more about a theme discussed on this page? Click on a link below to see all the pages on the Language Portal of Canada that relate to the theme you selected. The search results will be displayed in Language Navigator.

Date modified: