Tools

Cable Sizing Application

Click here to register to use our cable sizing application

What Changed

So that we can focus all our efforts on our new application, we have retired our myElectrical.com cable sizing calculator. We recommend you now use our main cable sizing application over at myCableEngineering.com.

myCableEngineering.com

Cable Sizing Software - select, size and manage your power cables using myCableEngineering. All your cables, for all your projects.
  • LV and MV cables up to 33 kV with current capacity in accordance with BS 7671, ERA 69-30 and IEC 60502.
  • Positive and zero sequence impedance to IEC 60609. Voltage drop in accordance with CENELEC CLC/TR 50480.
  • Project management and team collaboration, with clear easy to read calculations and reports.

Our software is the only cloud-based solution and has been built from the ground up to be fully responsive - meaning you can access your cables from anywhere and on any device, desktop, tablet or smartphone.

Duct Size Calculator


Tip: registered users can save calculations.

Typical Cable Diameters

Following outside diameters are for reference only and will vary depending on cable manufacturer. 

600/1000V XLPE Armoured

Overall Diameter (mm)
mm2 1core  2 core  3 core  4 core 
1.5    12.3  12.8  13.5
2.5    13.6  14.1  15.0
4    14.7  15.3  16.4
6    16.9  16.6  18.7
10    18.0  19.5  21.1
16     20.0  21.2  22.9
25    24.1  26.7  28.9
35    27.9  29.6  32.1
50*   17.5  25.8  28.5  32.0
70   20.2  29.0  32.2  37.7
95   22.3  33.1  37.0  41.7
120   24.2  36.1  40.0  47.7
150   27.4  39.3  45.5  51.4
185  30.0  44.7  49.8  56.6
 240  32.8  49.0  55.1  63.0
300  35.6  53.5  60.2  68.8
400  40.4  59.0  66.6  78.1
500  44.2      
630  48.8      
800  55.4      
1000  60.6      

 * - change in class of conductor

Calculation

1. Required fill factor k (in decimal)
2. Cable diameter d, giving a cable area, a:

a= π 4 d 2
3. Cable total area Ca = sum of area for all cables
4. Minimum duct diameter D:

D= 4 C a πk
Tips for a better Low Voltage Protection Discrimination Study

Carrying out a protection system discrimination study is critical to ensure the correct functioning of  the electrical system in the event of faults. ...

How to Calculate Motor Starting Time

Request to look at induction motor starting time have come up a few times on the site. Hopefully in this post, I give you guys some idea on how to calculate...

What is Aircraft Ground Power

Ever wondered what kind of power an aircraft uses when parked at the airport stand. Normally the aircraft generates it own power, but when parked with...

8 Steps to Low Voltage Power Cable Selection and Sizing

A recurring theme on our forums is cable sizing. Now many installations are unique and require special consideration. However, a lot of the time things...

Lithium Ion Battery

Over recent years the Lithium Ion battery has become popular in applications requiring high power densities with small weight and footprint.  Today Lithium...

Robotics - Home Innovations

We have a sister note to this (Robots - Interesting Video), in which I have posted some videos of interesting robots developed by commercial corporations...

How to refer fault levels across a transformer

Over the past year or so I've been involved in on going discussions related to referring fault levels from the secondary of a transformer to the primary...

Famous Scientists

Here’s list of some famous scientists. Deliberately short, with the aim to provide a quick memory jog or overview. If your looking for more detailed information...

Motor Insulation

Insulation on a motor prevents interconnection of windings and the winding to earth.  When looking at motors, it is important to understand how the insulation...

Low Voltage Circuit Breakers

Circuit breakers are switching devices whose primary function is to isolate parts of an electrical distribution system in the even of abnormal conditions...

Footer
(click here to extend)
Copyright (c) 2026 myElectrical