A variety of white schedule 40 pvc pipes in graduating sizes from small to large, arranged on a clean surface with a blurred warehouse background and the pvc fittings online logo on the left.

PVC Pipe Dimensions 1/8" through 24"

Written by: Mark Ligon

|

Published on

|

Time to read 3 min

Table of contents

Get dimensions to standard pipe sizing using the chart below.

Nominal Pipe Size O.D. Average I.D. Min. Wall Nominal wt./ft. Maximum W.P PSI
1/8" .405 .249 .068 .051 810
1/4" .540 .344 .088 .086 780
3/8" .675 .473 .091 .115 620
1/2" .840 .602 .109 .170 600
3/4" 1.050 .804 .113 .226 480
1" 1.315 1.029 .133 .333 450
1-1/4" 1.660 1.360 .140 .450 370
1-1/2" 1.900 1.590 .145 .537 330
2" 2.375 2.047 .154 .720 280
2-1/2" 2.875 2.445 .203 1.136 300
3" 3.500 3.042 .216 1.488 260
3-1/2" 4.000 3.521 .226 1.789 240
4" 4.500 3.998 .237 2.188 220
5" 5.563 5.016 .258 2.874 190
6" 6.625 6.031 .280 3.733 180
8" 8.625 7.942 .322 5.619 160
10" 10.750 9.976 .365 7.966 140
12" 12.750 11.889 .406 10.534 130
14" 14.000 13.073 .437 12.462 130
16" 16.000 14.940 .500 16.286 130
18" 18.000 16.809 .562 20.587 130
20" 20.000 18.743 .593 24.183 120
24" 24.000 22.544 .687 33.652 120

One of the most common things people get confused by with pipe is how it is sized and measured. PVC pipe can come in sizes ranging from 1/8" to 24" and larger. The table above shows sizing for schedule 40 PVC pipe in different sizes. You'll see this table shows the five most common pipe dimensions. Not sure what each of these are? Check our pipe measurement diagram here.

A graphic showing a cross-section of a 1-inch pvc pipe with a ruler next to it, showing that the nominal 1-inch size has an actual outer diameter (o.d.) of 1.315 inches.

Note: PVC pipe under 14" does not match up exactly with its nominal size (See Nominal Pipe Size and O.D. columns).

All the fittings we sell on our site are called by their nominal size. A 2" PVC fitting on our site will always fit a piece of 2" nominal size PVC pipe. Both schedule 40 and schedule 80 PVC fittings will fit onto PVC pipe of either schedule. That's because both types of pipe have the same outer diameter measurements. It is only the inner diameter measurement that is smaller on schedule 80 PVC, thus making for a thicker wall and higher pressure rating than sch. 40 pipe.

Nominal vs. Actual: PVC pipe is sized "nominally." For example, a 1" pipe actually has an outer diameter of 1.315".

The Compatibility Rule: Always match nominal sizes. A 2" fitting is designed to fit 2" pipe, regardless of whether the pipe is Schedule 40 or Schedule 80.

OD vs. ID: While Schedule 40 and 80 pipes have the same Outer Diameter (OD), Schedule 80 has a smaller Inner Diameter (ID) because its walls are thicker for higher pressure.

The 14" Shift: Note that for pipe sizes 14" and larger, the nominal size finally matches the actual outside diameter.

FAQs

Does the "Nominal Size" of a PVC pipe refer to its actual outside diameter?

No. The "Nominal" size is a name-only reference and does not match the actual physical outside diameter (O.D.). For example, a 1/2" nominal size PVC pipe actually has an outside diameter of 0.840", and a 2" nominal pipe has an outside diameter of 2.375". To ensure a proper fit, always match the nominal size of the pipe to the nominal size of the fitting.

How does the wall thickness and internal diameter change as the pipe size increases?

As the nominal size of the pipe increases, the minimum wall thickness also increases to maintain structural integrity. For instance, 1/8" Schedule 40 pipe has a wall thickness of 0.068", while 24" pipe has a wall thickness of 0.687". Consequently, while the outside diameter is fixed for each size, the average inside diameter (I.D.) is determined by subtracting the wall thickness from the O.D.

What is the maximum working pressure (PSI) for different PVC pipe sizes?

Generally, the maximum working pressure decreases as the pipe diameter increases. According to the Schedule 40 chart, small 1/8" pipe can handle up to 810 PSI, whereas large 24" pipe is rated for 120 PSI. These ratings are typically based on water at 73°F (23°C) and should be de-rated if the system is operating at higher temperatures.

Headshot of Mark Ligon

Mark Ligon

Mark Ligon is the marketing manager at PVC Fittings Online, a supplier of commercial PVC and CPVC pipe, fittings and valves. Ligon enjoys educating businesses on the parts of piping systems so managers can make informed decisions. He can be reached at webmaster@commercial-industrial-supply.com.

Related Blogs