Conduit Sizes Chart: EMT, Rigid & PVC OD and ID

Updated 2026-09-29

EMT (electrical metallic tubing) dimensions

EMT: outside diameter, inside diameter, wall and internal area
Trade size	OD in	OD mm	ID in	ID mm	Wall in	Area in²
1/2"	0.706	17.9	0.622	15.8	0.042	0.304
3/4"	0.922	23.4	0.824	20.9	0.049	0.533
1"	1.163	29.5	1.049	26.6	0.057	0.864
1-1/4"	1.510	38.4	1.380	35.1	0.065	1.496
1-1/2"	1.740	44.2	1.610	40.9	0.065	2.036
2"	2.197	55.8	2.067	52.5	0.065	3.356
2-1/2"	2.875	73.0	2.731	69.4	0.072	5.858
3"	3.500	88.9	3.356	85.2	0.072	8.846
3-1/2"	4.000	101.6	3.834	97.4	0.083	11.545
4"	4.500	114.3	4.334	110.1	0.083	14.753

Rigid metal conduit (RMC) dimensions

RMC: outside diameter, inside diameter, wall and internal area
Trade size	OD in	OD mm	ID in	ID mm	Wall in	Area in²
1/2"	0.840	21.3	0.632	16.1	0.104	0.314
3/4"	1.050	26.7	0.836	21.2	0.107	0.549
1"	1.315	33.4	1.063	27.0	0.126	0.887
1-1/4"	1.660	42.2	1.394	35.4	0.133	1.526
1-1/2"	1.900	48.3	1.624	41.2	0.138	2.071
2"	2.375	60.3	2.083	52.9	0.146	3.408
2-1/2"	2.875	73.0	2.489	63.2	0.193	4.866
3"	3.500	88.9	3.090	78.5	0.205	7.499
3-1/2"	4.000	101.6	3.570	90.7	0.215	10.010
4"	4.500	114.3	4.050	102.9	0.225	12.882

PVC conduit, Schedule 40 and 80

PVC conduit has the same outside diameter as rigid of the same trade size; Schedule 80 has a thicker wall and a smaller inside diameter.

PVC Schedule 40
Trade size	OD in	OD mm	ID in	ID mm	Wall in	Area in²
1/2"	0.840	21.3	0.602	15.3	0.119	0.285
3/4"	1.050	26.7	0.804	20.4	0.123	0.508
1"	1.315	33.4	1.029	26.1	0.143	0.832
1-1/4"	1.660	42.2	1.360	34.5	0.150	1.453
1-1/2"	1.900	48.3	1.590	40.4	0.155	1.986
2"	2.375	60.3	2.047	52.0	0.164	3.291
2-1/2"	2.875	73.0	2.445	62.1	0.215	4.695
3"	3.500	88.9	3.042	77.3	0.229	7.268
3-1/2"	4.000	101.6	3.521	89.4	0.239	9.737
4"	4.500	114.3	3.998	101.5	0.251	12.554

PVC Schedule 80
Trade size	OD in	OD mm	ID in	ID mm	Wall in	Area in²
1/2"	0.840	21.3	0.526	13.4	0.157	0.217
3/4"	1.050	26.7	0.722	18.3	0.164	0.409
1"	1.315	33.4	0.936	23.8	0.190	0.688
1-1/4"	1.660	42.2	1.255	31.9	0.203	1.237
1-1/2"	1.900	48.3	1.476	37.5	0.212	1.711
2"	2.375	60.3	1.913	48.6	0.231	2.874
2-1/2"	2.875	73.0	2.290	58.2	0.292	4.119
3"	3.500	88.9	2.864	72.7	0.318	6.442
3-1/2"	4.000	101.6	3.326	84.5	0.337	8.688
4"	4.500	114.3	3.786	96.2	0.357	11.258

Outside diameters are the standard manufactured sizes; inside diameters are derived from the NEC Chapter 9 Table 4 internal areas (d = √(4A ÷ π)), the values used for conduit fill.

Identifying conduit on site

Measure the outside diameter with a tape or calipers and match it to the tables: 0.706" is 1/2" EMT, 0.840" is 1/2" rigid or PVC.
EMT has no threads and joins with set-screw or compression fittings; rigid and IMC are threaded; PVC is grey and glued.
Rigid is one size "fatter" than EMT: 1/2" rigid (0.840") sits between 1/2" and 3/4" EMT (0.706" and 0.922"), which is why a 3/4" EMT shoe also bends 1/2" rigid.

Why the outside diameter matters for bending

Saddle depth over a pipe is its outside diameter plus clearance, not its trade size: a 2" rigid pipe needs about 2-3/8" of depth before clearance. And when you measure the legs of a 90 to its outside, the gain grows by one conduit diameter, which is why the back-to-back calculator and the deduct chart list both.

Questions electricians ask

What is the outside diameter of 3/4 EMT?

3/4" EMT is 0.922" (23.4 mm) outside and about 0.824" (20.9 mm) inside.

Is 1/2 inch conduit actually 1/2 inch?

No. Trade sizes are nominal. 1/2" EMT measures 0.706" outside and 0.622" inside; 1/2" rigid and PVC measure 0.840" outside.

Do EMT and rigid use the same fittings?

No. At the same trade size rigid has a larger outside diameter, so EMT set-screw or compression fittings do not fit rigid, and rigid is threaded. A 3/4" EMT hand bender bends 1/2" rigid because their sizes are close.