The Case of Capitalization in Electrical Units

In scientific and engineering writing, precision extends beyond calculations to the symbols themselves.

The International System of Units (SI) defines strict rules for capitalization that are often overlooked.

A core rule is that symbols derived from proper names are capitalized, while prefix symbols for multipliers less than a million are lowercase. For instance, the watt (W), volt (V), and ampere (A) honor scientists Watt, Volta, and Ampère, hence their uppercase letters. However, the prefix "kilo" (1,000) is always lowercase "k". This creates the correct forms kW, kV, and kA. Writing "KW" or "KV" is technically incorrect as "K" represents kelvin or 2¹⁰in computing contexts. Larger prefixes like mega (M) and giga (G) use uppercase.

Furthermore, non-proper units like meter (m) or second (s) remain lowercase. Adhering to kV over KV ensures clarity, respects scientific heritage, and avoids dangerous ambiguity in technical documentation. Mastering these details distinguishes professional engineering communication from casual approximation.