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Minimum Conductor Size
Voltage Drop Calculator
Note: Conductors must also be sized
for current carrying capacity.

Voltage Drop Calculator by
k=12.9 for copper
or k=21.2 for aluminum
Select Material

Select Voltage and Phase

Enter Maximum
voltage drop in per cent
Enter 1-way circuit
length in feet

Enter Load
in amperes
Calculated Voltage drop
Voltage at load
end of circuit
Calculated CMA of
CMA of
Size of

CMA = circular mil area from NEC Chapter 9 Table 8.