off-grid solar and wind power specialists

Cable Size Calculator Tool - DC Power Cables

Correct cable size is important on low voltage systems !

DC Power Cable Sizing - Online Calculator

Our online cable or wire size calculator tool makes it easy to establish the correct size of cables for any DC power system. 

Please feel welcome to bookmark/digg/xmark this page now and have access to the tool whenever you need it - share it with friends, colleagues, anyone who has to deal with DC electrical cables.

Cable sizes are particularly important for low voltage battery cables, solar panels, wind turbines and load cables.

Voltage drops through incorrectly sized cables are one of the most common reasons for low voltage (12v, 24v or 48v) system faults. If the cable is far too small, it can be very dangerous as the cable will heat up and potentially cause a fire. Undersized cables also waste energy.

Conversely, too large a cable and you are simply wasting your money on good copper.

We hope you find the tool useful.

How To Use The Cable Size Calculator

To use the calculator :

1 - Enter percentage cable loss acceptable [normally approx 2 or 3%].
2 - Enter system voltage.
3 - Enter max amps to be carried by the cable [amps = watts / voltage].
4 - Enter max length of cable run required.
5 - Click "Calculate" - results are shown in the closest standard metric & AWG cable sizes.

Acceptable Loss

Vdc - System Voltage

Amps (Watts/Voltage)

Length of Cable Run (m)

Matched mm˛ Cable Size Required

Matched AWG Cable Size Required

All cable sizes given on this page refer to single core HO7RNF rubber insulated cable, at an ambient temperature of 30 deg C, and a conductor temperature of 85 deg C max.

Cable sizes should only be used as a guideline and if not using HO7RNF cable, all figures should be checked against the manufacturers data sheet. Also, all cables should be fused / current protected to their max rating or less.

Disclaimer : We ( accept no legal liability for any issues caused by using this cable sizing calculator.

High Quality Flexible Power Cable

View our range of heavy duty, flexible rubber HO7RNF cables ... we can supply cable sizes from 1.5mm2 to 400mm2.

Use the correct size of cable ...

About Us

At the EDC, we design off-grid power systems for commercial, domestic, leisure and marine applications. We supply a wide range of solar panels, wind generators, batteries and inverters.

This web site provides in-depth information regarding off-grid solar or wind power systems. Please feel free to look around and if you require any assistance please don't hesitate to contact us.

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