AWG / kcmil to mm²

Conductor cross-sections for American Wire Gauge and kcmil sizes in mm², with the solid-wire diameter and the IEC 60228 size nearest in area.

Conversion table 30 sizes

↓ CSV

Size	Area (kcmil)	Area (mm²)	Solid Ø (in)	Solid Ø (mm)	Nearest IEC (mm²)	Next larger IEC (mm²)
AWG
18 AWG	1.624	0.823	0.0403	1.02	0.75	1
16 AWG	2.583	1.309	0.0508	1.29	1.5	1.5
14 AWG	4.107	2.081	0.0641	1.63	2.5	2.5
12 AWG	6.530	3.309	0.0808	2.05	4	4
10 AWG	10.4	5.261	0.1019	2.59	6	6
8 AWG	16.5	8.366	0.1285	3.26	10	10
6 AWG	26.3	13.30	0.1620	4.12	16	16
4 AWG	41.7	21.15	0.2043	5.19	25	25
3 AWG	52.6	26.67	0.2294	5.83	25	35
2 AWG	66.4	33.63	0.2576	6.54	35	35
1 AWG	83.7	42.41	0.2893	7.35	35	50
1/0 AWG	105.5	53.48	0.3249	8.25	50	70
2/0 AWG	133.1	67.43	0.3648	9.27	70	70
3/0 AWG	167.8	85.03	0.4096	10.40	95	95
4/0 AWG	211.6	107.22	0.4600	11.68	95	120
kcmil
250 kcmil	250.0	126.68	0.5000	12.70	120	150
300 kcmil	300.0	152.01	0.5477	13.91	150	185
350 kcmil	350.0	177.35	0.5916	15.03	185	185
400 kcmil	400.0	202.68	0.6325	16.06	185	240
500 kcmil	500.0	253.35	0.7071	17.96	240	300
600 kcmil	600.0	304.02	0.7746	19.67	300	400
700 kcmil	700.0	354.70	0.8367	21.25	400	400
750 kcmil	750.0	380.03	0.8660	22.00	400	400
800 kcmil	800.0	405.37	0.8944	22.72	400	500
900 kcmil	900.0	456.04	0.9487	24.10	500	500
1000 kcmil	1,000.0	506.71	1.0000	25.40	500	630
1250 kcmil	1,250.0	633.38	1.1180	28.40	630	800
1500 kcmil	1,500.0	760.06	1.2247	31.11	800	800
1750 kcmil	1,750.0	886.74	1.3229	33.60	800	1000
2000 kcmil	2,000.0	1,013.41	1.4142	35.92	1000	—

How this table is generated

d(n) = 0.005 in × 92^((36 − n) / 39) A = (1000 · d)² [circular mils] mm² = cmil × π/4 × 0.0254²

n is the gauge number, with 1/0 = 0, 2/0 = −1, 3/0 = −2 and 4/0 = −3. The AWG series is defined geometrically between 0.005 in (36 AWG) and 0.46 in (4/0), so every value here is computed, not transcribed. kcmil sizes are areas by definition (1 kcmil = 1000 circular mils ≈ 0.5067 mm²).

Solid Ø is the diameter of a solid round conductor of that area. Stranded conductors are larger in diameter; use the manufacturer's data for outside dimensions.

Using the IEC columns

AWG and IEC 60228 sizes do not line up. Nearest is closest in area and can be smaller than the AWG size. Next larger is the smallest IEC size with at least the same area. Area alone does not establish equivalence: ampacity, voltage drop and termination suitability must be checked for the size actually used.

IEC 60228 nominal sizes considered: 0.5, 0.75, 1, 1.5, 2.5, 4, 6, 10, 16, 25, 35, 50, 70, 95, 120, 150, 185, 240, 300, 400, 500, 630, 800, 1000 mm².

Cable Check — current, size adequacy and voltage drop for a cable you specify.

Sources: AWG geometric definition (ASTM B258 describes the gauge series); IEC 60228 is cited for its nominal size designations only. Values are computed by RokBench. © RokBench.