Electrical Wire Gauge Chart: AWG Sizes, Ampacity, and Residential Uses
Selecting the correct wire gauge is the most fundamental decision in any electrical project. Undersized wire is a fire hazard. Oversized wire wastes money. The American Wire Gauge (AWG) system assigns numbers to wire sizes, with a counterintuitive relationship: the larger the AWG number, the thinner the wire. This guide provides a complete residential wire gauge reference with ampacity ratings, breaker sizes, and common applications for each gauge.
Understanding AWG Numbers
AWG numbers run from 0000 (4/0, the thickest common residential conductor) down through single digits to 14 AWG and 16 AWG for branch circuit work. As the AWG number increases, the wire diameter decreases and the resistance per foot increases, reducing the safe current-carrying capacity. This inverse relationship surprises many buyers: 12 AWG wire is thicker and carries more current than 14 AWG wire, despite the smaller number.
Residential Wire Gauge Reference Chart
14 AWG: Maximum 15 amps. Paired with 15-amp breaker. Uses: general lighting circuits, bedroom and living area outlets, hallway lighting, closet lighting, smoke detector circuits. Cable type: 14/2 or 14/3 NM-B.
12 AWG: Maximum 20 amps. Paired with 20-amp breaker. Uses: kitchen countertop outlets (code required), bathroom outlets (code required), garage outlets (code required), outdoor receptacles, laundry room outlets, dishwasher circuits, garbage disposal circuits. Cable type: 12/2 or 12/3 NM-B, 12/2 MC cable.
10 AWG: Maximum 30 amps. Paired with 30-amp breaker. Uses: electric dryer circuits, electric water heater circuits, 30-amp Level 2 EV charger circuits, window AC disconnect feeds, hot tub sub-feeds. Cable type: 10/2 or 10/3 NM-B, 10/2 UF-B for outdoor runs.
8 AWG: Maximum 40 amps. Paired with 40-amp breaker. Uses: electric range sub-feed, 40-amp Level 2 EV charger circuits, large AC equipment disconnects, small subpanel feeds. Cable type: 8/3 NM-B or individual THHN conductors in conduit.
6 AWG: Maximum 55 amps. Paired with 50 to 60-amp breaker. Uses: electric range circuits (full 50-amp range circuit), large AC equipment, small subpanel feeds of 50 to 60 amps, generator transfer switch feeds for smaller generators. Cable type: 6/3 NM-B or THHN in conduit, SER cable for service entrance applications.
4 AWG: Maximum 70 amps. Paired with 70-amp breaker. Uses: 60 to 70-amp subpanel feeds, medium generator transfer switch feeds, large HVAC equipment. Cable type: THHN in conduit or SER service entrance cable.
2 AWG: Maximum 95 amps. Paired with 90 to 100-amp breaker. Uses: 100-amp subpanel feeds to detached garages, workshops, and outbuildings. Cable type: THHN in conduit or SER cable.
1 AWG: Maximum 110 amps. Uses: large subpanel feeds and service entrance conductors for smaller services.
1/0 AWG (one-aught): Maximum 125 amps. Uses: 125-amp service entrance conductors, large subpanel feeds.
2/0 AWG (two-aught): Maximum 145 amps. Uses: service entrance conductors for 150-amp services, large subpanel feeds.
3/0 AWG (three-aught): Maximum 165 amps. Uses: service entrance conductors for 175-amp services.
4/0 AWG (four-aught): Maximum 195 amps. Paired with 200-amp breaker (with appropriate derating). Uses: 200-amp residential service entrance, large commercial subpanel feeds.
The Critical Rule: Wire Gauge Must Match the Breaker
The circuit breaker protects the wire from overheating by tripping when current exceeds a safe threshold. If the breaker is rated higher than the wire can safely carry, the breaker will not trip before the wire overheats. This is how electrical fires start. Always match: 14 AWG wire on a 15-amp breaker, 12 AWG wire on a 20-amp breaker, 10 AWG wire on a 30-amp breaker. You may use larger wire on a smaller breaker (12 AWG on a 15-amp breaker is safe, just wasteful), but never smaller wire on a larger breaker.
Voltage Drop Consideration
AWG ampacity charts are based on conductor temperature limits under continuous load, not on voltage drop performance. For long circuit runs (typically 75 feet or more for 120-volt circuits, or 150 feet or more for 240-volt circuits), voltage drop becomes a concern even if the wire is correctly sized for ampacity. The NEC recommends keeping voltage drop to 3% or less for branch circuits. For long runs, upsizing one AWG (using 10 AWG where 12 AWG meets the ampacity requirement) maintains acceptable voltage at the load end.
IB Lighting carries all common residential wire gauges in NM-B, UF-B, MC, and THHN from Southwire and Cerrowire. Browse our complete wire and cable selection or call (800) 674-9019 for help selecting the right gauge and cable type for your project. Free freight insurance on every order. Guidance informed by IB Lighting master electrician expertise.