Instruction manual

AWG Wire Sizes (see table on the next page)

AWG: In the American Wire Gauge (AWG), diameters can be calculated by applying the formula

D(AWG)=.005·92((36-AWG)/39) inch. For the 00, 000, 0000 etc. gauges you use -1, -2, -3, which makes

more sense mathematically than “double nought.” This means that in American wire gage every 6 gauge

decrease gives a doubling of the wire diameter, and every 3 gauge decrease doubles the wire cross sectional

area. Similar to dB in signal and power levels. An approximate form of this formula contributed by Mario

Rodriguez is D = .460 * (57/64)(awg +3) or D = .460 * (0.890625)(awg +3).

Metric Wire Gauges (see table on the next page)

Metric Gauge: In the Metric Gauge scale, the gauge is 10 times the diameter in millimeters, so a 50 gauge

metric wire would be 5 mm in diameter. Note that in AWG the diameter goes up as the gauge goes down, but

for metric gauges it is the opposite. Probably because of this confusion, most of the time metric sized wire is

Load Carr ying Capacities (see table on the next page)

The following chart is a guideline of ampacity or copper wire current carrying capacity following the Handbook

of Electronic Tables and Formulas for American Wire Gauge. As you might guess, the rated ampacities are

just a rule of thumb. In careful engineering the voltage drop, insulation temperature limit, thickness, thermal

conductivity, and air convection and temperature should all be taken into account. The Maximum Amps for

Power Transmission uses the 700 circular mils per amp rule, which is very conservative. The Maximum

Amps for Chassis Wiring is also a conservative rating, but is meant for wiring in air, and not in a bundle. For

short lengths of wire, such as is used in battery packs you should trade off the resistance and load with size,