10 AWG voltage drop at 250 feet
Computed voltage drop for 10 AWG copper conductors on a 250 ft one-way run.
14.52 V
drop on 10 AWG copper, 250 ft one-way, 24 A load · 12.1% of 120 V · 6.0% of 240 V
10 AWG at 250 ft by load
| Load | Drop | % at 120 V | % at 240 V | 3% rule (240 V) |
|---|---|---|---|---|
| 6 A | 3.63 V | 3.0% | 1.5% | OK |
| 12 A | 7.26 V | 6.0% | 3.0% | OK at 240 V up to 5% |
| 18 A | 10.89 V | 9.1% | 4.5% | OK at 240 V up to 5% |
| 24 A | 14.52 V | 12.1% | 6.0% | Upsize |
Vd = 2 × length × R × I ÷ 1000, R = 1.21 Ω/1000 ft (copper, NEC Ch. 9 Table 8). Aluminum is about 1.6× higher.
Same wire, other distances
25 ft · 50 ft · 75 ft · 100 ft · 125 ft · 150 ft · 200 ft · 300 ft
FAQ
What is the voltage drop on 10 AWG wire at 250 feet?
At 24 A (80% of its 30 A 75°C rating) 10 AWG copper drops 14.52 V over 250 ft one-way: 12.1% at 120 V or 6.0% at 240 V.
How far can I run 10 AWG at 24 amps?
To stay within 3% at 120 V, about 62 ft one-way; at 240 V about 124 ft.