PVC Pipe Sizes Chart

Quick answer: PVC pipe is sold by nominal pipe size, not by the exact outside or inside diameter. For example, 1/2-inch Schedule 40 PVC has a 0.840-inch outside diameter and about a 0.622-inch inside diameter. Use nominal size for buying pipe and fittings, but use actual ID, OD, and wall thickness when checking flow, clearance, or project fit.

How To Read PVC Pipe Dimensions

Nominal size: the trade size used to buy pipe and fittings.
OD: outside diameter. PVC fittings are based around this dimension.

ID: inside diameter. This affects flow and what can pass through the pipe.
Minimum wall: the minimum wall thickness for the schedule or pipe class.

Schedule 80 has the same outside diameter as Schedule 40 in the same nominal size, but it has a thicker wall and therefore a smaller inside diameter. That is why a 1-inch Schedule 40 pipe and a 1-inch Schedule 80 pipe fit the same nominal fitting family but do not have the same internal opening.

PVC Schedule 40 Sizes Chart

Nominal pipe size	Outside diameter	Approx. inside diameter	Minimum wall	Common use note
1/2 in	0.840 in	0.622 in	0.109 in	Small water lines, DIY frames, light irrigation
3/4 in	1.050 in	0.824 in	0.113 in	Small irrigation and light shop projects
1 in	1.315 in	1.049 in	0.133 in	General residential and shop utility runs
1-1/4 in	1.660 in	1.380 in	0.140 in	Higher-flow drain, vent, or irrigation sections
1-1/2 in	1.900 in	1.610 in	0.145 in	Common for drains, vents, and larger water movement
2 in	2.375 in	2.067 in	0.154 in	Garage drains, sump/discharge routing, dust collection experiments
3 in	3.500 in	3.068 in	0.216 in	Larger drain and vent work
4 in	4.500 in	4.026 in	0.237 in	Main drainage and large air/dust routing projects

PVC Schedule 80 Sizes Chart

Nominal pipe size	Outside diameter	Approx. inside diameter	Minimum wall	What changes vs. Schedule 40
1/2 in	0.840 in	0.546 in	0.147 in	Thicker wall, smaller ID
3/4 in	1.050 in	0.742 in	0.154 in	Thicker wall, smaller ID
1 in	1.315 in	0.957 in	0.179 in	Better for higher-demand applications
1-1/4 in	1.660 in	1.278 in	0.191 in	More wall thickness than Schedule 40
1-1/2 in	1.900 in	1.500 in	0.200 in	Stronger wall, reduced flow area
2 in	2.375 in	1.939 in	0.218 in	Useful when strength matters more than maximum flow
3 in	3.500 in	2.900 in	0.300 in	Much thicker wall and smaller ID
4 in	4.500 in	3.826 in	0.337 in	Heavy-wall option for larger lines

PVC Thinwall And SDR Sizes

Thinwall PVC is often labeled by SDR, which means standard dimension ratio. SDR compares pipe outside diameter to wall thickness. A lower SDR number means a thicker wall. Thinwall pipe may be useful for drainage, vents, sleeves, low-pressure irrigation, and lightweight shop projects, but it should not be substituted into pressure work unless the pipe marking, rating, and local code allow it.

Pipe type	What it means	Typical use	Buying caution
Schedule 40 PVC	Common pressure-rated PVC with moderate wall thickness	General pressure and utility work where allowed	Check temperature and pressure rating printed on pipe
Schedule 80 PVC	Same nominal OD with a thicker wall and smaller ID	Higher-demand systems, threaded sections, industrial-style setups	Costs more and flows less than same-size Schedule 40
SDR 21 PVC	Thinwall pressure pipe with wall thickness based on OD ratio	Irrigation and some water-service applications	Do not assume it matches Schedule 40 fittings in every project
DWV PVC	Drain, waste, and vent pipe	Non-pressure drainage and venting	Not for compressed air or pressure systems

Which PVC Size Should You Use?

For fittings and replacement parts, start with the nominal size printed on the pipe. For flow, clearance, or inserting another object inside the pipe, use the actual inside diameter. For brackets, holes, clamps, and pass-throughs, use the outside diameter. If the project carries water, air, gas, chemicals, or pressure, verify the pipe rating and local code before installing anything permanent.

Source Notes

Dimensions were cross-checked against PVC Schedule 40 and Schedule 80 dimension references from Engineering ToolBox, Spears Schedule 40 technical data, and Spears Schedule 80 technical data. Always use the rating printed on the actual pipe for pressure-sensitive work.