> Voltage Drop Calculator for AC single phase and DC circuits

Cable Size Calculator

Cable Voltage Drop Calculator

Set Cable size from strands	Strand diameter (mm)
	Strand count

Set Cable size from AWG/B&S cable size

DC Voltage drop at 25°C cable temperature	Cable size (mm²)
	Length (metres)
	Max current (amps)
	Voltage drop (volts)
DC Voltage drop at other temperatures	Cable Temperature (°C)
DC Voltage drop at other temperatures	Voltage drop (volts)
Approx AC 50Hz Voltage drop at other temperatures
Approx AC 50Hz Voltage drop at other temperatures	Voltage drop (volts)

Notes: Cable temperature is the actual temperature of the copper, not the ambient air temperature. Cable length is the total circuit length.

AC Voltage drop calculation is approxmately 10.02% larger than dc values for cables sizes between 2.5mm2 to 25mm2 at 50Hz. For larger cables the voltage drop gets worse, eg:- 50mm2 18%, 120mm2 22%, 150mm2 29.4%, 300mm2 68.4%, 630mm2 is a crazy 278.5%. This means that large conductors at 50Hz become a waste of copper, due to skin effect.

Required size at 25°C cable temperature	Length (metres)
	Max current (amps)
	Allowable voltage drop (volts)
	Required Cable size (mm²)

Required size at other temperatures	Cable Temperature (°C)
	Required Cable size (mm²)