I can't find this anywhere else on the internet so I thought I'd post it here. There is an old rule of thumb for calculating the voltage drop of copper wire.
The Rule of Fourteen
14 AWG, 14 Amps,14 feet has about a 1 volt drop.This scales so 14 AWG, 14 Amps 1.4 feet has about a 0.1 volt drop.
For each increase in AWG the current drops by 1dB (10log) or about
0.8.so for 16 AWG, 14 feet, (0.8)*(0.8)*14Amps = 8.96 has a 1 volt drop.
Try it