Cable size calculator to calculate the required cable sizes for various types of cables, installation methods, correction factors and protective devices to BS 7671 18th edition 2018.

Carry out on the spot instant cable calculations, great for electrical surveys, EICR, circuit design and cable sizing on the go.

Also checks the volt drop and max Zs and applies the relevant correction factors from an easy to select list of options.

Calculate circuit cable sizes for mains cable final circuits and distribution sub main supplies.

Can also be used to check the electrical cable ratings for different electrical installation methods to ensure existing cables or wires are compliant on existing installations for an Electrical Installation Condition Report (EICR) including volt drop and Max Zs.

You can also use this app to check existing installed cables and circuits to check for compliance and confirm the correct cable size for the type of cable, installation method and length of circuit.

Functions Include:
+ Verification checks and helpful hints
+ Support for manufacturer specific BS EN 60947-2
(max Zs) MCCB's & ACB's
+ Support for RCD's in TT Earthing Systems

This app also takes into account and applies the following factors for it's calculations:
+ Volt drop
+ Correction factors
+ Maximum disconnection times
+ Length of circuit
+ Various installation methods
+ Various cable types
+ Tabulated Current
+ Maximum Zs Values
+ Calculates Zs
+ Calculates r1+r2
+ Calculates volt drop
+ Calculates PSSC
+ Adjusted required minimum required cable ratings
+ Calculates cable size

Correction Factors Include:
+ Cg - Grouping
+ Ca - Ambient air temperature
+ Ca - Ambient ground temperature (if cable is buried
or in a duct)
+ Ci - Thermal insulation
+ Cf - BS 3036 semi-enclosed fuses (rewireable

Mobile cable sizing software.
Check out our suite of electrical apps @

What’s New

Version 1.3

Thank you for downloading this cable sizer calculation app, this update brings UI enhancements and bug fixes.


Pro Certs Software Ltd
4.3 MB

Requires iOS 8.0 or later. Compatible with iPhone, iPad, and iPod touch.



Age Rating
Rated 4+
© Pro Certs Software Ltd


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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