AWG 24 wire size, resistance and weight calculator
AWG 24 is defined by the gauge formula, not by a table: the diameter is 0.127 mm times 92 raised to the power (36 - n) / 39. Everything else follows from that and the conductor resistivity.
A rough guide: 3 to 5 A/mm2 for chassis wiring, under 2 for long runs in conduit.
- Diameter
- 0.510 559
- Area in circular mils
- 0.404 04
- Resistance of that length
- 8.420 83 ohm
- Resistance per kilometre
- 84.2083 ohm/km
- Resistance per 1000 feet
- 25.6667 ohm
- Weight of that length
- 0.183 438
- Current at the chosen density
- 0.82 A
- Turns per centimetre, close-wound
- 19.586
Show the working
- Length of wire = 100
- Conductor = 1.724e-8
- Conductor temperature = 20
- Conductor density = 8960
- Design current density = 4
- Diameter = 0.127 * 92^((36 - (24)) / 39) = 0.510 559
- diameter_in = 0.510 559 / 25.4 = 0.020 100 8
- Cross-sectional area = pi * 0.510 559^2 / 4 = 0.204 73
- Area in circular mils = 0.020 100 8^2 * 1000 = 0.404 04
- r_per_m_20 = 1.724e-8 / (0.204 73 * 1e-6) = 0.084 208 3
- r_per_m = 0.084 208 3 * (1 + 0.00393 * (20 - 20)) = 0.084 208 3
- Resistance of that length = 0.084 208 3 * 100 = 8.420 83
- Resistance per kilometre = 0.084 208 3 * 1000 = 84.2083
- Resistance per 1000 feet = 0.084 208 3 * 304.8 = 25.6667
- Weight of that length = 0.204 73 * 1e-6 * 100 * 8960 = 0.183 438
- Current at the chosen density = 0.204 73 * 4 = 0.818 921
- Turns per centimetre, close-wound = 0.510 559 > 0 ? 10 / 0.510 559 : 0 = 19.5864
Values are shown to six significant figures here; the arithmetic itself runs on exact fractions and is only rounded where a number is printed.
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The formula
- diameter in mm = 0.127 x 92^((36 - n)/39)
- area = pi d^2 / 4
- resistance = rho x length / area
- temperature correction: R(T) = R(20) x (1 + 0.00393 (T - 20)) for copper
The gauge formula is exact: 36 AWG is 0.127 mm and 0000 AWG is 11.684 mm, with 39 steps between them in a geometric progression of ratio 92^(1/39).
The current figure is a design rule of thumb from current density, not an ampacity rating. Real ampacity depends on insulation temperature rating, bundling, ambient temperature and the wiring code in force.
Aluminium conductors of the same gauge carry about 61% of the current of copper for the same heating.
Frequently asked
What is the diameter of AWG 24 wire?
It follows from the gauge definition: 0.127 mm x 92^((36 - n)/39). The calculator shows the result in millimetres and inches.
Why does the wire gauge number go down as the wire gets thicker?
The number counts drawing operations. Each pass through a die makes the wire thinner and adds one to the gauge, so a high number means a thin wire.