Voltage Drop Calculator

Voltage Drop Formula

The voltage drop formula is expressed as Voltage Drop = ( mV/A/m ) x L x Ib / 1000.

• mV = millivolts

• A = Amps

• L = Cable Length in meters

• Ib = Design Current in Amps

• / = Divide by 1000 to convert the result from Millivolts to Volts

mV/A/m = millvolts per Amp per Meter.

To find the mV/A/m for a type of cable, the volt drop per Amp per meter values are listed in Appendix 4 of BS 7671, however we can save you the hassle and time, as we have already programmed these values directly in to this Voltage Drop Calculator (including a correction factor for temperature).

Not only will this voltage drop calculator calculate the voltage drop in Volts, it will also calculate the voltage drop percent (%).

Try the Voltage Drop Calculator