Conductor Ampacity Lookup

CSA C22.1:24 Tables 1–4 ampacity for copper and aluminum conductors. Includes ambient temperature correction (Table 5A) and conduit fill adjustment (Table 5C). Updated for the 2024 code cycle — values unchanged from 2021, but mm² size column was removed and heading wording changed from "Allowable ampacities" to "Ampacities".

Inputs

Conductor Material

Insulation Rating

Conductor Size

Ambient Temperature (°C)

Base temperature: 30°C (Table 5A correction applies)

Conductors in Raceway/Cable

Table 5C correction for 4+ current-carrying conductors

Results

Base Ampacity (Table 2/4)

—

amperes

Temp Correction

—

— A after correction

Fill Correction

—

— A after correction

Corrected Ampacity

—

amperes (after all corrections)

OESC Reference

Table 2 (Cu, 75°C)

How It Works

Tables 1–4: Table 1 covers copper conductors in free air, Table 2 covers copper in raceway/cable, Table 3 covers aluminum in free air, and Table 4 covers aluminum in raceway/cable. Each table has columns for 60°C, 75°C, and 90°C insulation ratings.

Table 5A (Temperature Correction): When ambient temperature differs from 30°C, ampacity is corrected by a factor. For temperatures above 30°C, ampacity decreases. For temperatures below 30°C, ampacity increases (up to a limit).

Table 5C (Conductor Fill): When 4+ current-carrying conductors are bundled in a raceway or cable, ampacity is reduced: 4-6 conductors → 80%, 7-24 → 70%, 25-42 → 60%, 43+ → 50%.

Reference Tables

Table 1 — Single Copper Conductors in Free Air

Ampacities for single copper conductors, bare/covered/insulated, ≤5000 V, unshielded, in free air. Ambient 30°C. See Rules 4-004, 4-006, 26-142, 42-008, 42-016, Tables 5A, 5B, 19.

Size (AWG/kcmil)	60°C	75°C	90°C	110°C	125°C	200°C
14	25	30	35	40	40	50
12	30	35	40	45	45	55
10	40	50	55	65	65	80
8	60	70	80	90	95	115
6	80	95	105	120	130	155
4	105	125	140	160	170	205
3	120	145	165	185	195	240
2	140	170	190	215	230	280
1	165	195	220	245	265	320
0	195	230	260	290	310	375
00	220	265	300	335	355	435
000	260	310	350	390	420	510
0000	300	360	405	455	485	590
250	340	405	455	510	545	—
300	370	445	500	560	600	—
350	425	505	570	640	680	—
400	455	545	615	690	735	—
500	520	620	700	785	835	—
600	580	690	780	870	930	—
700	630	755	850	955	1020	—
750	655	785	885	990	1060	—
800	680	815	920	1030	1100	—
900	730	870	980	1100	1175	—
1000	785	935	1055	1180	1260	—
1250	890	1065	1200	1345	—	—
1500	985	1175	1325	1485	—	—
1750	1070	1280	1445	1620	—	—
2000	1160	1385	1560	1750	—	—

* See Table 5A for correction factors at ambient temps over 30°C. See Table 5B for 2–4 conductors in contact. 2024 change: "Allowable ampacities" heading shortened to "Ampacities". mm² column removed.

Table 2 — ≤3 Insulated Copper Conductors in Raceway/Cable

Ampacities for not more than three insulated copper conductors, ≤5000 V, unshielded, in raceway or cable. Ambient 30°C. See Rules 4-004, 26-142, 42-008, 42-016, Tables 5A, 5C, 19, D3.

Size (AWG/kcmil)	60°C	75°C	90°C	110°C	125°C	200°C
14	15	20	25	25	30	35
12	20	25	30	30	35	40
10	30	35	40	45	45	60
8	40	50	55	65	65	80
6	55	65	75	80	90	110
4	70	85	95	105	115	140
3	85	100	115	125	135	165
2	95	115	130	145	155	190
1	110	130	145	165	175	215
0	125	150	170	190	200	245
00	145	175	195	220	235	290
000	165	200	225	255	270	330
0000	195	230	260	290	310	380
250	215	255	290	320	345	—
300	240	285	320	360	385	—
350	260	310	350	390	420	—
400	280	335	380	425	450	—
500	320	380	430	480	510	—
600	350	420	475	530	565	—
700	385	460	520	580	620	—
750	400	475	535	600	640	—
800	410	490	555	620	660	—
900	435	520	585	655	700	—
1000	455	545	615	690	735	—
1250	495	590	665	745	—	—
1500	525	625	705	790	—	—
1750	545	650	735	820	—	—
2000	555	665	750	840	—	—

* See Table 5A for ambient temp correction, Table 5C for 4+ current-carrying conductors.

Table 3 — Single Aluminum Conductors in Free Air

Ampacities for single aluminum conductors, bare/covered/insulated, ≤5000 V, unshielded, in free air. Ambient 30°C. See Rules 4-004, 26-142, 42-008, 42-016, Tables 5A, 5B, 19.

Size (AWG/kcmil)	60°C	75°C	90°C	110°C	125°C	200°C
12	25	30	35	40	40	50
10	35	40	45	50	55	65
8	45	55	60	70	75	90
6	65	75	85	95	100	125
4	85	100	115	125	135	165
3	95	115	130	145	155	190
2	115	135	150	170	180	220
1	130	155	175	195	210	255
0	150	180	205	225	245	295
00	175	210	235	265	285	345
000	200	240	270	305	325	395
0000	235	280	315	355	375	460
250	265	315	355	400	425	—
300	295	350	395	440	470	—
350	330	395	445	500	535	—
400	355	425	480	535	575	—
500	405	485	545	615	655	—
600	455	545	615	690	735	—
700	500	595	670	750	800	—
750	520	620	700	785	835	—
800	540	645	725	815	870	—
900	585	700	790	885	945	—
1000	630	750	845	950	1010	—
1250	715	855	965	1080	—	—
1500	795	950	1070	1200	—	—
1750	880	1050	1185	1325	—	—
2000	965	1150	1295	1455	—	—

Table 4 — ≤3 Insulated Aluminum Conductors in Raceway/Cable

Ampacities for not more than three insulated aluminum conductors, ≤5000 V, unshielded, in raceway or cable. Ambient 30°C. See Rules 4-004, 26-142, 42-008, 42-016, Tables 5A, 5C.

Size (AWG/kcmil)	60°C	75°C	90°C	110°C	125°C	200°C
12	15	20	25	25	25	35
10	25	30	35	40	40	50
8	35	40	45	50	55	65
6	40	50	55	65	70	80
4	55	65	75	80	90	105
3	65	75	85	95	100	125
2	75	90	100	115	120	150
1	85	100	115	125	135	165
0	100	120	135	150	160	195
00	115	135	150	170	180	220
000	130	155	175	195	210	255
0000	150	180	205	225	245	295
250	170	205	230	260	275	—
300	195	230	260	290	310	—
350	210	250	280	315	335	—
400	225	270	305	340	365	—
500	260	310	350	390	420	—
600	285	340	385	430	460	—
700	315	375	425	475	505	—
750	320	385	435	485	520	—
800	330	395	445	500	535	—
900	355	425	480	535	575	—
1000	375	445	500	560	600	—
1250	405	485	545	615	—	—
1500	435	520	585	655	—	—
1750	455	545	615	690	—	—
2000	470	560	630	710	—	—

Table 5A — Ambient Temperature Correction Factors

Correction factors for Tables 1, 2, 3, 4, and 60 at ambient temperatures above 30°C. See Rules 4-004 7) and 16-330.

Ambient °C	60°C	75°C	90°C	105°C	110°C	125°C	150°C	200°C	250°C
35	0.91	0.94	0.96	0.97	0.97	0.97	0.98	0.99	0.99
40	0.82	0.88	0.91	0.93	0.94	0.95	0.96	0.97	0.98
45	0.71	0.82	0.87	0.89	0.90	0.92	0.94	0.95	0.97
50	0.58	0.75	0.82	0.86	0.87	0.89	0.91	0.94	0.95
55	0.41	0.67	0.76	0.82	0.83	0.86	0.89	0.92	0.94
60	—	0.58	0.71	0.77	0.79	0.83	0.87	0.91	0.93
65	—	0.47	0.65	0.73	0.75	0.79	0.84	0.89	0.92
70	—	0.33	0.58	0.68	0.71	0.76	0.82	0.87	0.90
75	—	—	0.50	0.63	0.66	0.73	0.79	0.86	0.89
80	—	—	0.41	0.58	0.61	0.69	0.76	0.84	0.88
90	—	—	—	0.45	0.50	0.61	0.71	0.80	0.85
100	—	—	—	0.26	0.35	0.51	0.65	0.77	0.83
110	—	—	—	—	—	0.40	0.58	0.73	0.80
120	—	—	—	—	—	0.23	0.50	0.69	0.77
130	—	—	—	—	—	—	0.41	0.64	0.74
140	—	—	—	—	—	—	0.29	0.59	0.71

2024 note: Column references shifted from "3 to 8" (2021) to "2 to 7" (2024) due to mm² size column removal in Tables 1–4.