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How many amps can 14 AWG wire carry?

20 A — copper at 75 °C, NEC Table 310.16.

14 AWG copper carries 20 A at 75 °C, 15 A at 60 °C and 25 A at 90 °C under NEC Table 310.16, before derating. NEC 240.4(D) then caps the breaker at 15 A, so 15 A is the usable answer. Aluminum is not rated at this size.

Safety first. These figures are an educational reference before derating, not a code substitute. Verify against the current NEC and have circuits reviewed by a licensed electrician.

14 AWG ampacity — copper vs aluminum

14 AWG ampacity by conductor material and insulation temperature rating.
Material 60 °C 75 °C 90 °C Breaker cap
Copper 15 A 20 A 25 A 15 A
Aluminum not rated not rated not rated —

Values are amps at a 30 °C ambient, before derating for temperature or conductor bundling. Most installations must use the 75 °C column regardless of the wire's own rating, because terminals and breakers are rated 75 °C (NEC 110.14(C)).

How far can you run 14 AWG at 15 A?

Ampacity answers whether a conductor will overheat. It says nothing about whether the voltage still arrives at the far end. Past roughly fifty feet, voltage drop is usually what really sets the wire size. These are the longest one-way runs that keep drop within the 3% recommended by the NEC 210.19(A) informational note, for 14 AWG copper carrying 15 A.

Maximum one-way run length for 14 AWG copper at 15 A by system voltage.
System Typical use Max run at 3% Drop at 100 ft
120 V standard receptacle and lighting circuits 48 ft 7.58 V
240 V ranges, dryers, EV chargers, feeders 95 ft 7.58 V
12 V DC automotive, marine, solar and battery runs 5 ft 7.58 V

Single-phase, one-way distance, copper at 20 °C. Aluminum reaches its limit at roughly 60% of these distances for the same size. The 3% figure is a recommendation in an informational note, not a code requirement.

14 AWG wire size — diameter, area and resistance

Diameter

0.0641 in · 1.628 mm

Cross-section

2.081 mm² · 4,107 cmil

Nearest metric size

2.5 mm² (rounds up)

Copper resistance

2.5254 Ω per 1000 ft @ 20 °C

Aluminum resistance

4.2174 Ω per 1000 ft

Area

4.107 kcmil

Diameter is computed from the ASTM B258 definition d = 0.005 × 92^((36 − n)/39), not read from a rounded table. Resistance uses the annealed-copper constant 10.371 Ω·cmil/ft at 20 °C.

What 14 AWG wire is used for

The 14 gauge mistake worth knowing

14 AWG copper is 15 A and must never sit on a 20 A breaker — the most dangerous and most common wire-size error in residential work, because 14 and 12 AWG look nearly identical once stripped.