ElectricalCharts

14 AWG Wire Specs

Ampacity, geometry, resistance, conduit fill and maximum run length for 14 AWG conductors in copper and aluminium.

Quick answer

14 AWG copper carries about 18 A at 75 °C (15 A at 60 °C, 20 A at 90 °C). The bare conductor is 0.0641 in (1.63 mm) and 4,107 circular mils, with 2.5252 Ω per 1000 ft. It pairs with a 15 A breaker at 75 °C terminations.

Copper 75 °C

18A

Aluminium 75 °C

14A

Diameter

0.0641in

Circular mils

4,107

Full specification

Size designation14 AWG
AWG gauge number14
Circular mils4,107
kcmil4.11
Bare diameter (in)0.0641
Bare diameter (mm)1.628
Cross-section (mm²)2.08
THHN/THWN-2 OD (in)0.111
Insulated area (sq in)0.0097
Copper resistance (Ω/1000 ft)2.5252
Aluminium resistance (Ω/1000 ft)4.1393
Max standard breaker (Cu, 75 °C)15 A
Published standard — source: Geometry computed from the ASTM B258 AWG formula; resistance from standard resistivityFormula estimate — source: Ampacity from the site model

Ampacity with derating

Estimated ampacity from the 90 °C column at various ambient temperatures and conductor counts.

Conductors in raceway30 °C ambient40 °C ambient50 °C ambient60 °C ambient
320 A18 A16 A14 A
616 A15 A13 A11 A
914 A13 A11 A10 A
1510 A9 A8 A7 A
259 A8 A7 A6 A

Source & method: The governing value is also capped by the termination rating, commonly 75 °C, which for this size is 18 A. Run your own conditions.

Maximum run length at 3% voltage drop

One-way distance for 14 AWG copper before drop exceeds 3%.

Load120 V 1Ø240 V 1Ø208 V 3Ø480 V 3Ø
10 A57 ft114 ft114 ft264 ft
15 A38 ft76 ft76 ft176 ft
20 A28 ft57 ft57 ft132 ft
30 A19 ft38 ft38 ft88 ft
40 A14 ft28 ft28 ft66 ft
50 A11 ft22 ft22 ft52 ft

Calculate your exact run

How many 14 AWG conductors fit in conduit

Maximum count of this size alone, at the fill percentage matching the resulting count.

Conduit1/2"3/4"1"1-1/4"1-1/2"2"2-1/2"3"3-1/2"4"
EMT1222356184138242365400400
IMC1424396891150212327400400
RMC1222366385140201309400400
PVC Sch 401120346082136194300400400
PVC Sch 80816285170118170266359400

Mix conductor sizes in the fill calculator

Neighbouring sizes

Smaller16 AWG13 A copper at 75 °C · 0.0508" diameterLarger12 AWG24 A copper at 75 °C · 0.0808" diameter

Frequently asked

How many amps can 14 AWG wire carry?
14 AWG copper is estimated at 15 A at 60 °C, 18 A at 75 °C and 20 A at 90 °C, at 30 °C ambient with no more than three current-carrying conductors. Aluminium of the same size is about 14 A at 75 °C.
What breaker size goes with 14 AWG copper?
The largest standard overcurrent device that 14 AWG copper supports at 75 °C is 15 A. For a continuous load, the load itself must not exceed 80% of that rating.
What is the diameter of 14 AWG wire?
The bare conductor is 0.0641 inches (1.628 mm) in diameter, which is 4,107 circular mils. With THHN/THWN-2 insulation the nominal outside diameter is about 0.111 inches.
What is the resistance of 14 AWG wire?
About 2.5252 ohms per 1000 feet for copper and 4.1393 ohms per 1000 feet for aluminium, at 75 °C.
How far can I run 14 AWG wire?
Distance depends on load and voltage. At 20 A on a 120 V single-phase circuit, 14 AWG copper stays under 3% voltage drop for about 28 feet one-way. Doubling the voltage roughly doubles the allowable distance.

Materials for this size

Materials for this size

Wire, cable and terminations for 14 AWG.

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