Wire Gauge / AWG Calculator

American Wire Gauge (AWG) reference and calculators. Look up wire properties, calculate voltage drop over a run, and find the minimum gauge for any circuit.

AWG Wire Properties Lookup

Select a gauge and application to see diameter, cross-section, resistance, and rated current capacity.

AWG Gauge

Application / Temp Rating

Remember: Higher AWG number = thinner wire. AWG 30 is hair-thin; AWG 4/0 is thumb-thick. Always verify the rated ampacity for your specific wire insulation and installation method.

Voltage Drop Calculator

Calculates round-trip (there and back) resistive voltage drop for a DC circuit. NEC recommends ≤3% for branch circuits, ≤5% total from service panel.

AWG Gauge

One-Way Length

Load Current

Supply Voltage

Round trip: Voltage drop uses the full circuit length — wire going to the load plus wire coming back. A 25ft run means 50ft of current path.

Wire Sizer — Find Minimum AWG

Enter your circuit requirements and get the lightest wire gauge that keeps voltage drop within your limit. Also checks ampacity rating.

Load Current

One-Way Length

Supply Voltage

Max Voltage Drop

Application

Always verify: The sizer checks voltage drop and the table ampacity for the application you pick, nothing more. Local codes, conduit fill, insulation type, and ambient temperature may require a heavier gauge. When in doubt, go one size heavier.

Complete AWG Reference Table

All standard AWG gauges. Ampacity ratings per UL/NEC guidelines at stated temperature. Resistance at 20°C (68°F) copper conductor.

NEC 60°C column: NEC Table 310.16, copper, 60°C insulation, no more than three current-carrying conductors in a raceway or cable, 30°C ambient. It gives no 60°C value for 16 or 18 AWG; as fixture wire (Table 402.5) they are rated 8 A and 6 A. Derate for a hotter ambient or more conductors, and size continuous loads at 125%.

AWG	Dia. (mm)	Dia. (in)	Area (mm²)	Ω/1000 ft	Ω/100 m	Chassis 60°C (A)	Power 75°C (A)	Hot 90°C (A)	NEC 60°C (A)