Cable & Installation

Choose the cable construction and how it will be installed.

Cable Type

Installation Method

Supply & Load

Enter the supply voltage and the load the circuit must carry.

Supply Voltage (V)

Typical: 110V site / 230V single-phase / 415V three-phase Enter a positive voltage.

Phase

Auto-suggested from voltage; override if needed.

Load

For motor applications, enter 4× the rated power/current to account for starting load. Enter a positive load.

Allowable Voltage Drop (%)

BS 7671 recommends ≤ 3% for lighting and ≤ 5% for other uses. Enter a value between 1 and 10.

Cable Length (m)

One-way run length. Enter a length of at least 1 m.

Correction Factors (optional)

Adjust for environment and grouping per BS 7671 Tables 4B1 & 4C1.

Ambient Temperature

Grouping

Results

Required Cable Size —

Load Current —

Voltage Drop —

Percentage Drop —

Recommended Fuse / MCB —

Status

⚠ For guidance only. No guarantee of accuracy. All values must be verified by a qualified electrician in accordance with BS 7671 / IET Wiring Regulations 18th Edition.

Cable Size Calculator

Cable & Installation

Supply & Load

Correction Factors (optional)

Results