PVC pipe is wider than its nominal size. 1/2" PVC is 0.840" (21.3 mm) across in both Schedule 40 and Schedule 80, and Schedule 80’s thicker wall leaves it narrower inside.
PVC pipe size chart
PVC pipe size chart
| Size | Outside (OD) | Schedule 40 inside | Schedule 80 inside |
|---|---|---|---|
| 1/8" | 0.405" (10.3 mm) | 0.249" (6.3 mm) | n/a |
| 1/4" | 0.540" (13.7 mm) | 0.344" (8.7 mm) | 0.282" (7.2 mm) |
| 3/8" | 0.675" (17.1 mm) | 0.473" (12.0 mm) | 0.403" (10.2 mm) |
| 1/2" | 0.840" (21.3 mm) | 0.602" (15.3 mm) | 0.526" (13.4 mm) |
| 3/4" | 1.050" (26.7 mm) | 0.804" (20.4 mm) | 0.722" (18.3 mm) |
| 1" | 1.315" (33.4 mm) | 1.029" (26.1 mm) | 0.936" (23.8 mm) |
| 1-1/4" | 1.660" (42.2 mm) | 1.360" (34.5 mm) | 1.255" (31.9 mm) |
| 1-1/2" | 1.900" (48.3 mm) | 1.590" (40.4 mm) | 1.476" (37.5 mm) |
| 2" | 2.375" (60.3 mm) | 2.047" (52.0 mm) | 1.913" (48.6 mm) |
| 2-1/2" | 2.875" (73.0 mm) | 2.445" (62.1 mm) | 2.290" (58.2 mm) |
| 3" | 3.500" (88.9 mm) | 3.042" (77.3 mm) | 2.864" (72.7 mm) |
| 3-1/2" | 4.000" (101.6 mm) | 3.521" (89.4 mm) | 3.326" (84.5 mm) |
| 4" | 4.500" (114.3 mm) | 3.998" (101.5 mm) | 3.786" (96.2 mm) |
| 5" | 5.563" (141.3 mm) | 5.016" (127.4 mm) | 4.768" (121.1 mm) |
| 6" | 6.625" (168.3 mm) | 6.031" (153.2 mm) | 5.709" (145.0 mm) |
| 8" | 8.625" (219.1 mm) | 7.942" (201.7 mm) | 7.565" (192.2 mm) |
| 10" | 10.750" (273.1 mm) | 9.976" (253.4 mm) | 9.493" (241.1 mm) |
| 12" | 12.750" (323.8 mm) | 11.889" (302.0 mm) | 11.294" (286.9 mm) |
Outside: Charlotte Pipe’s and Spears’ tables, which agree. Inside: Spears’ average. n/a: Spears lists no Schedule 80 at 1/8".
| Size | Schedule 40 wall | Schedule 80 wall |
|---|---|---|
| 1/8" | 0.068" | n/a |
| 1/4" | 0.088" | 0.119" |
| 3/8" | 0.091" | 0.126" |
| 1/2" | 0.109" | 0.147" |
| 3/4" | 0.113" | 0.154" |
| 1" | 0.133" | 0.179" |
| 1-1/4" | 0.140" | 0.191" |
| 1-1/2" | 0.145" | 0.200" |
| 2" | 0.154" | 0.218" |
| 2-1/2" | 0.203" | 0.276" |
| 3" | 0.216" | 0.300" |
| 3-1/2" | 0.226" | 0.318" |
| 4" | 0.237" | 0.337" |
| 5" | 0.258" | 0.375" |
| 6" | 0.280" | 0.432" |
| 8" | 0.322" | 0.500" |
| 10" | 0.365" | 0.593" |
| 12" | 0.406" | 0.687" |
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Schedule 40 or Schedule 80
At each size the two schedules have the same outside diameter, so a 2" pipe is 2.375" across whichever schedule it is. Charlotte Pipe’s Schedule 40 is white and its Schedule 80 dark gray, both made to ASTM D1785.
Only Schedule 80 or heavier PVC should be threaded. Don’t thread Schedule 40 or thin-wall class pipe such as SDR 21 and SDR 26.
Class 200 and Class 160 pipe
Thin-wall PVC sold by class, such as Class 200 (SDR 21) and Class 160 (SDR 26), has the same outside as Schedule 40 at each size. Its thinner wall gives it a larger inside.
| Size | Outside (OD) | Class 200 inside | Class 160 inside |
|---|---|---|---|
| 3/4" | 1.050" | 0.910" | n/a |
| 1" | 1.315" | 1.169" | 1.175" |
| 1-1/4" | 1.660" | 1.482" | 1.512" |
| 1-1/2" | 1.900" | 1.700" | 1.734" |
| 2" | 2.375" | 2.129" | 2.173" |
| 2-1/2" | 2.875" | 2.581" | 2.635" |
| 3" | 3.500" | 3.146" | 3.210" |
| 4" | 4.500" | 4.046" | 4.134" |
Spears’ tables. Class 160 starts at 1".
Drain pipe and other PVC
- DWV drain pipe: Charlotte Pipe’s solid-wall 1-1/2", 2" and 4" Schedule 40 is marked for both pressure (ASTM D1785) and drain (ASTM D2665) use. Its foam core drain pipe has the same outside and is for drainage only.
- 4" sewer pipe: thin-wall sewer and drain pipe made to ASTM D3034 or ASTM D2729 is 4.215" across, smaller than 4" Schedule 40. See 4" pipe OD.
- CTS CPVC: CPVC made to copper tube size, such as Charlotte Pipe’s FlowGuard Gold, is narrower, at 0.625" across for 1/2". See CPVC to PVC.
- Different sizing systems: pipe made to different outside diameters doesn’t interchange, though a specialty adapter fitting can often join them.
Measuring PVC pipe
Measure across the outside with a caliper and match it to the OD column. The two schedules measure the same outside, so to tell them apart, check the wall at a cut end against the wall table. For one size across every kind of pipe, see 1/2", 3/4", 1", 1-1/2", 2" and 4" pipe OD.