14 AWG Voltage Drop Chart
14 AWG copper wire has a resistance of 3.14 ohms per 1000 feet. NEC 240.4(D) and the standard ampacity tables cap this gauge at 15A for a branch-circuit breaker (60°C ampacity: 15A; 75°C: 20A). At 100 feet on a 120V circuit, it stays under 3% voltage drop up to about 5A.
14 AWG Wire Specifications
| Property | Value |
|---|---|
| Gauge | 14 AWG |
| Resistance (copper) | 3.14 Ω per 1000ft |
| Ampacity (60°C) | 15A |
| Ampacity (75°C) | 20A |
| NEC branch-circuit OCP | 15A (capped by NEC 240.4(D)) |
| Amps that land on 3% drop at 100ft (120V) | ~5A |
Voltage Drop by Amps & Distance (120V)
Green = within the 3% branch-circuit drop target, Amber = 3-5% (past branch target, within 5% feeder+branch total), Red = past the 5% feeder+branch total recommendation
When to Use 14 AWG
Typical applications: Residential branch circuits: lighting, outlets, and small appliance circuits.
Under typical 75°C-termination assumptions, 14 AWG is commonly protected by up to 15A branch-circuit OCP (NEC 240.4(D) caps it here even though the 75°C ampacity table lists 20A). Real install ceilings depend on conductor and termination temperature ratings, cable type (NM-B is limited to the 60°C column in residential use, so the usable value is lower), NEC 310.15(C)(1) bundling adjustments, and NEC 310.15(B) ambient corrections. Even with ampacity margin, longer runs may fall outside the 3% branch-circuit drop target recommended in NEC 210.19(A) Informational Note 4, which is why the distance table above matters.
Compared to Adjacent Gauges
| Gauge | Resistance | Ampacity (75°C) | Drop at 20A/100ft (120V) |
|---|---|---|---|
| 14 AWG | 3.14 Ω/kft | 20A | 10.47% |
| 12 AWG (thicker) | 1.98 Ω/kft | 25A | 6.6% |