Number of wires conductor

The number of wires are given in the IEC 60228 Ed.3.0 and the draft IEC NP 62602 from 2015, more values were taken from ASTM B8-04.

For aluminium conductors where no number of wires is given in the standards, the number from the equivalent copper conductor is taken.
For shaped conductors where no number of wires is given in the standards, the number from compacted conductors is taken.
For sizes of 1200 mm$^2$ and above for stranded and flexible class 5/6 conductors, values from ASTM B8-04 were taken and interpolated.
For sizes of 1200 mm$^2$ and above for milliken and compacted conductors, the number was set to 271 (approximating a solid conductor which leads to high values for the K-factors).
For sizes of 2.5 mm$^2$ and smaller, a solid conductor is assumed which is normally the case for electric power cables for installation. The conductors down to 2.5 mm$^2$ are listed with 6, respectively 7 wires as appropriate.
The values for 12 and 10 AWG for compacted and shaped conductors, the number was set to 6 instead of solid conductor.
The values for 1250, 1500 and 1750 kcmil for compacted aluminium conductors and for shaped conductors were interpolated from metric sizes and set to 53.

Symbol

$n_{cw}$

Related

$A_c$

Cross-sectional area conductor [mm$^2$]

$c_{type}$

Construction conductor

$K_{BICC}$

Constant relating to conductor formation

$K_{GMR}$

Factor geometric mean radius

$M_c$

Conductor material

Used in

$R_{co}$

Standard DC resistance of conductor [$\Omega$/km]

Choices

Size	$A_{c}$	circular Cu	Al	compact Cu	shaped Cu	Al	flexible class 5/C	class 6/D	Value
26 AWG	0.128	1	1	1	1	1	1	1	1
24 AWG	0.205	1	1	1	1	1	1	19	19
22 AWG	0.324	1	1	1	1	1	1	19	19
0.5 mm$^2$	0.5	1	1	1	1	1	1	19	19
20 AWG	0.519	1	1	1	1	1	1	19	19
0.75 mm$^2$	0.75	1	1	1	1	1	1	19	19
18 AWG	0.823	1	1	1	1	1	1	19	19
1.0 mm$^2$	1	1	1	1	1	1	1	19	19
16 AWG	1.31	1	1	1	1	1	1	19	19
1.5 mm$^2$	1.5	1	1	1	1	1	1	19	19
14 AWG	2.08	1	1	1	1	1	1	19	37
2.5 mm$^2$	2.5	1	1	1	1	1	1	19	37
12 AWG	3.31	7	7	6	6	6	6	19	37
4 mm$^2$	4.0	7	7	6	6	6	6	19	37
10 AWG	5.261	7	7	6	6	6	6	19	37
6 mm$^2$	6.0	7	7	6	6	6	6	19	37
8 AWG	8.367	7	7	7	7	7	7	19	37
10 mm$^2$	10.0	7	7	6	6	6	6	19	37
6 AWG	13.3	7	7	7	7	7	7	19	37
16 mm$^2$	16.0	7	7	6	6	6	6	19	37
4 AWG	21.15	7	7	7	7	7	7	19	37
25 mm$^2$	25.0	7	7	6	6	6	6	19	37
3 AWG	26.67	7	7	7	7	7	7	19	37
2 AWG	33.62	7	7	7	7	7	7	19	37
35 mm$^2$	35.0	7	7	6	6	6	6	19	37
1 AWG	42.41	19	19	18	18	18	18	37	61
50 mm$^2$	50.0	19	19	6	6	6	6	37	61
1/0 AWG	53.49	19	19	18	18	18	18	37	61
2/0 AWG	67.43	19	19	18	18	15	15	37	61
70 mm$^2$	70.0	19	19	12	12	12	12	37	61
3/0 AWG	85.01	19	19	18	18	15	15	37	61
95 mm$^2$	95.0	19	19	18	15	18	15	37	61
4/0 AWG	107.2	19	19	18	18	15	15	37	61
120 mm$^2$	120.0	37	37	18	15	18	15	37	61
250 kcmil	127.0	37	37	35	35	28	28	61	91
150 mm$^2$	150.0	37	37	18	15	18	15	61	91
300 kcmil	152.0	37	37	35	35	28	28	61	91
350 kcmil	177.0	37	37	35	35	28	28	61	91
185 mm$^2$	185.0	37	37	30	30	30	30	61	91
400 kcmil	203.0	37	37	35	35	28	28	61	91
240 mm$^2$	240.0	37	37	34	30	34	30	61	91
500 kcmil	253.0	37	37	35	35	28	28	61	91
300 mm$^2$	300.0	61	61	34	30	34	30	61	91
600 kcmil	304.0	61	61	58	35	28	28	91	127
700 kcmil	355.0	61	61	58	47	47	47	91	127
750 kcmil	380.0	61	61	58	47	47	47	91	127
400 mm$^2$	400.0	61	61	53	53	53	53	91	127
800 kcmil	405.0	61	61	58	47	47	47	91	127
900 kcmil	456.0	61	61	58	47	47	47	91	127
500 mm$^2$	500.0	61	61	53	53	53	53	91	127
1000 kcmil	507.0	61	61	58	47	47	47	91	127
630 mm$^2$	630.0	91	91	53	53	53	53	127	169
1250 kcmil	633.0	91	91	91	53	53	53	127	169
1500 kcmil	760.0	91	91	91	53	53	53	127	169
800 mm$^2$	800.0	91	91	53	53	53	53	127	169
1750 kcmil	887.0	91	91	91	53	53	53	169	219
1000 mm$^2$	1000.0	91	91	53	53	53	53	169	219
2000 kcmil	1013.0	127	127	127	127	127	127	169	219
2250 kcmil	1140.0	127	127	127	127	127	127	169	219
1200 mm$^2$	1200.0	127	127	271	271	271	271	169	219
2500 kcmil	1270.0	127	127	271	271	271	271	169	219
1400 mm$^2$	1400.0	127	127	271	271	271	271	169	219
2750 kcmil	1393.0	169	169	271	271	271	271	217	217
3000 kcmil	1520.0	169	169	271	271	271	271	217	271
1600 mm$^2$	1600.0	169	169	271	271	271	271	217	271
3500 kcmil	1770.0	169	169	271	271	271	271	217	271
1800 mm$^2$	1800.0	169	169	271	271	271	271	217	271
2000 mm$^2$	2000.0	217	217	271	271	271	271	271	271
4000 kcmil	2030.0	217	217	271	271	271	271	271	271
4500 kcmil	2280.0	217	217	271	271	271	271	271	271
2500 mm$^2$	2500.0	217	217	271	271	271	271	271	271
5000 kcmil	2530.0	217	217	271	271	271	271	271	271
3000 mm$^2$	3000.0	217	217	271	271	271	271	271	271
3200 mm$^2$	3200.0	217	217	271	271	271	271	271	271
3500 mm$^2$	3500.0	217	217	271	271	271	271	271	271