Methodology

Where the numbers come from and how each result is derived.

Every calculator on Wire & Voltage works from a table transcribed out of a published wiring standard, and every constant in the source carries an inline comment naming the table or rule it came from. Nothing is a magic number.

Standards transcribed

  • NEC — NFPA 70: National Electrical Code (United States)
  • BS 7671 — BS 7671: Requirements for Electrical Installations (IET Wiring Regulations) (United Kingdom)
  • AS/NZS 3000 — AS/NZS 3000: Electrical Installations (Wiring Rules) (Australia)

What this page will cover

  • The derivation behind each calculator, step by step
  • Which edition of each standard the tables are transcribed from
  • Rounding and significant-figure policy
  • How corrections are reported and reviewed

This page is a stub. The per-calculator derivations land alongside the calculators themselves.