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
Back to basics - the Watt (or kW)

When thinking about watts (W) or kilowatt (kW = 1000 W) it can be useful too keep in mind the fundamental ideas behind the unit. Watt is not a pure electrical...

Cost Performance and Time

Often us engineers get so bogged down in equations, using software, producing drawings and writing specifications that this becomes the sole focus.   ...

Michael Faraday (the father of electrical engineering)

Famed English chemist and physicist Michael Faraday was born on September 22, 1791, in Newington Butts, a suburb of Surrey just south of the London Bridge...

DC Motor Operation

Coils of wire on the rotor carry a d.c. current which generates a magnetic field. A stator magnetic field is created using either permanent magnets or...

Post Authorship

In 2011, with the introduction of it’s Panda search ranking algorithms, Google introduced tools for determining the original author of posts.  The intention...

Fire Resistant and Fire Retardant Cables

Fire resistant and fire retardant cable sheaths are design to resist combustion and limit the propagation of flames. Low smokes cables have a sheath designed...

Electromechanical Relays

Electromechanical relays have been the traditional backbone of electrical protection systems.  While over recent years these have been replaced by microprocessor...

Introduction to Lighting

When looking at the design of a lighting scheme it is useful to have an understanding on the nature of light itself and some of the basic theory associated...

Are We Losing Professional Integrity

I have been thinking recently that there appears to be less professional integrity around than when I first started my career in electrical engineering...

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...

Footer
(click here to extend)
Copyright (c) 2025 myElectrical