14 AWG voltage drop at 25 feet
Computed voltage drop for 14 AWG copper conductors on a 25 ft one-way run.
1.84 V
drop on 14 AWG copper, 25 ft one-way, 12 A load · 1.5% of 120 V · 0.8% of 240 V
14 AWG at 25 ft by load
| Load | Drop | % at 120 V | % at 240 V | 3% rule (240 V) |
|---|---|---|---|---|
| 3 A | 0.46 V | 0.4% | 0.2% | OK |
| 6 A | 0.92 V | 0.8% | 0.4% | OK |
| 9 A | 1.38 V | 1.2% | 0.6% | OK |
| 12 A | 1.84 V | 1.5% | 0.8% | OK |
Vd = 2 × length × R × I ÷ 1000, R = 3.07 Ω/1000 ft (copper, NEC Ch. 9 Table 8). Aluminum is about 1.6× higher.
Same wire, other distances
50 ft · 75 ft · 100 ft · 125 ft · 150 ft · 200 ft · 250 ft · 300 ft
FAQ
What is the voltage drop on 14 AWG wire at 25 feet?
At 12 A (80% of its 15 A 75°C rating) 14 AWG copper drops 1.84 V over 25 ft one-way: 1.5% at 120 V or 0.8% at 240 V.
How far can I run 14 AWG at 12 amps?
To stay within 3% at 120 V, about 49 ft one-way; at 240 V about 98 ft.