Wire Gauge Chart

How to read the American wire gauge chart

The American wire gauge chart looks arbitrary until you learn its three shortcuts. Every 3 gauge steps double the copper cross-section — 10 AWG (5.26 mm²) holds twice the copper of 13 AWG. Every 6 steps double the diameter — 8 AWG (3.26 mm) is twice the width of 14 AWG (1.63 mm). And every 10 steps multiply resistance by about 6. With those, you can interpolate any size from a few anchors instead of memorizing forty rows.

One habit worth forming: distinguish solid diameters from stranded bundles. A 12 AWG solid wire measures exactly 2.05 mm across, while a stranded bundle is larger outside but carries the same copper — the stranded wire gauge chart explains strand classes and equivalence rules. Our complete American wire gauge chart tabulates 4/0 through 40 AWG, including the "aught" sizes (1/0–4/0) used in service work and the kcmil ladder beyond them.

Wire gauge chart amps: matching size to current

Thickness buys current capacity, so the wire gauge chart amps view is the busiest corner of this site. Our wire gauge amp chart collects the NEC Table 310.16 ampacity ratings for copper and aluminium at 60/75/90 °C, 14 AWG through 4/0, plus the breaker caps that matter most in homes: 15 A protection for 14 AWG, 20 A for 12 AWG, 30 A for 10 AWG. For whole circuits — lighting, receptacles, dryers, ranges — the electrical wire gauge chart names the standard copper size each load needs.

Ampacity is only half the decision. A long 12 AWG run at 20 A can pass every heat test and still lose more than 3% of its voltage on the way, starving motors and dimming loads. The wire size calculator below checks both limits at once — amps, voltage, one-way length, conductor metal and system type — and tells you which limit forced the size up.

12V DC wire gauge chart: distance is the enemy

Low-voltage systems invert the rules. At 12 volts, 5% loss is just 0.6 V and the same wattage draws ten times the current of a 120 V load — so the gauge is decided by amps × distance, not by breaker size. Our 12V DC wire gauge chart gives quick picks for lighting, pumps, fridges and inverters, with the round-trip resistance math shown in Ω/ft and a fuse-placement rule worth reading twice.

The same physics runs the automotive wire gauge chart (chassis free-air ratings, TXL/GXL insulation, grounding notes), the low voltage wire gauge chart for 18–12 AWG doorbell, thermostat, security and irrigation work, and the speaker wire gauge chart, which keeps the round-trip resistance under 5% of speaker impedance so bass stays tight.

Actual size wire gauge chart: thickness at a glance

Screens do not show you what 0.81 mm feels like. The actual size wire gauge chart prints true-scale circles for the popular gauges — lay a stripped wire on a circle and the size matches in one second. The sheet includes a 100 mm calibration strip and a credit-card outline, so you can catch a printer that silently "scaled to fit" the page and inflated every circle by up to 5%.

Printed at true diameter, it doubles as a thickness actual size wire gauge chart for guessing unlabeled wire in drawers: 26–30 AWG runs sewing-thread fine, 16 AWG is about a spaghetti strand, and 4/0 dwarfs a pen cap.

Copper wire gauge chart: material and construction matter

Copper is the default conductor for a reason, and the copper wire gauge chart lists its exact resistance ladder — Ω/1000 ft and Ω/km at 20 °C for every size, next to the ampacity that matters. Aluminium needs about 64% more cross-section for the same resistance plus rated terminations; copper-clad aluminium trades ~10% more resistance for less weight. Flexing projects — battery leads, headphone cords, motor whips — want stranded; permanent terminals accept solid. The rule is always the same: more copper cross-section, less resistance, less voltage drop, less heat. If you only know the amps and the length, let the calculator pick the gauge; if you only know the diameter, let the converter find the AWG.

Jewelry and craft wire gauge charts

Fine wire work speaks the gauge chart in millimeters and tempers. Wire-wrapped rings and clasps use 18–20 AWG (1.02–1.29 mm); bead links and ear wires sit at 22–24; coiling and weaving drop to 26–30 AWG, where copper behaves like soft thread. The jewelry wire gauge chart maps each size to bead-hole compatibility and explains temper; the craft wire gauge chart covers florals, wreath frames, armatures and decor ties with a starting pick for each. Both borrow their numbers from the same formula as the electrical charts, so nothing disagrees when a project crosses from craft wire into lamp cord.

Common AWG sizes at a glance

A few anchors cover most everyday questions: 10 AWG is 2.59 mm and the 30 A circuit size; 12 AWG is 2.05 mm on 20 A breakers; 14 AWG is 1.63 mm on 15 A circuits; 18 AWG (1.02 mm) is lamp and thermostat cord; 20 AWG (0.81 mm) is classic electronics hookup; 26 AWG (0.41 mm) is jumper and craft wire; 30 AWG (0.25 mm) is coil-wrap and repair wire. Every size has its own detail page with area, resistance and amp rating — same formula, same source of truth.

How to use the wire size calculator, and why to trust it

Scroll up and enter four numbers: load current, system voltage, one-way length, and the maximum voltage drop you accept (3% is a solid default; 5% suits general loads). Pick the conductor metal and the system — DC, single-phase or three-phase — and the calculator returns the minimum gauge that clears ampacity and voltage-drop together, names the deciding limit, and shows the voltage that actually arrives at the load. The tool runs on the same NEC table and the same AWG formula behind every chart on this site, so they never disagree. What the numbers cannot see — insulation temperature, bundling, ambient heat, local code — is why mains wiring still belongs to a licensed electrician.