PVC follows iron pipe size (IPS), so it shares outside diameters with steel pipe of the same schedule. This chart gives Schedule 40 PVC outside and inside diameters.
| Nominal | OD (in) | Sch 40 ID |
|---|---|---|
| 1/2 in | 0.840 | 0.602 |
| 3/4 in | 1.050 | 0.804 |
| 1 in | 1.315 | 1.029 |
| 1-1/2 in | 1.900 | 1.610 |
| 2 in | 2.375 | 2.067 |
| 3 in | 3.500 | 3.068 |
| 4 in | 4.500 | 4.026 |
Nominal is not the OD. Like steel, a 1-inch PVC pipe has a 1.315 in outside diameter. Schedule 80 has thicker walls and a smaller bore for higher pressure.
See the Pipe Schedule Chart and Pipe Thread Dimensions.