Cable Sizing Calculator BS 7671

Automatic cable sizing, voltage drop, correction factors, fault loop, conduit sizing, and short circuit calculations.

British Cable Sizing Standard

Standards and Compliance

  • This cable sizing calculator complies with BS 7671 The IET Wiring Regulations, providing accurate results for:
  • Current-carrying capacity.
  • Voltage drop based on resistance and reactance, cable operating temperature, and load power factor.
  • Short-circuit performance.
  • Neutral and earth sizing.
  • Voltage range: Up to and including 0.6/1 kV AC (1.5 kV DC).
  • Temperature range: Based on typical Australian installation conditions Air 30 °C and Soil 15°C.
  • Installation methods: Covers various methods, including buried and unenclosed installations.

Key Features

  • Auto-size or manual selection.
  • Supports 1ph, 3ph, DC, and 2ph systems with copper and aluminium conductors.
  • Accurate voltage drop/rise calculations.
  • Fault loop impedance check.
  • Correction factors.
  • Protective devices including MCB, MCCB, ACB, fuses, and custom.
  • Conduit sizing based on actual cable diameters.
  • Short-circuit rating.
  • Professional reports.
  • Live instantaneous results: This calculator provides instant results, allowing for quick iterations and design optimisation.