Schedule 40 and Schedule 80 PVC Pipe Sizes

5th Jan 2024

Schedule 40 and Schedule 80 PVC Pipe Sizes

Size Chart and How to Measure

PVC pipe is a versatile material that ranges in size from a 1/8-inch diameter to two feet or more, but that doesn’t refer to the total diameter of the pipe. Tradesmen and DIYers can get into an inconvenient situation when they find that they’ve ordered the size they think they need, but it doesn’t fit. This happens because the listed sizes of PVC pipes refer to the nominal diameter, which is based on the average inner diameter (ID). You can get around this issue by calling up your supplier and telling them your specs or by learning to measure PVC on your own.

How to Measure PVC Pipe

The reason PVC pipe is measured using the nominal diameter is that pipes and fittings use a nominal system. That means compatible parts are given the same name (size) to make matching easier. A two-inch fitting will match up with a two-inch pipe because the average inner diameter of that pipe is about two inches and the outer diameter (male) or inner diameter (female) of the fitting is two inches. Again, the nominal diameter is based on the average inner diameter of the pipe. It’s not an exact match.
To maintain structural integrity, the walls of the PVC pipe must get thicker as the diameter of the pipe increases, so you can’t just add a certain amount to the inner diameter of the pipe to get your outer diameter. Unless you have the pipe and you’re able to measure, you’ll have to know the thickness of the walls to translate one measurement to the other. If you do have the pipe on hand, you can probably find the size (nominal diameter) of the pipe printed down the side. If not, here’s how you measure for both the inner and outer diameters to get the nominal diameter:

To find the outer diameter:

  • Wrap a string around the pipe.
  • Mark the points where the string meets.
  • Use a ruler or measuring tape to find the length between the marks on the string.
  • Divide this measurement by 3.14159. This is your outer diameter.
  • Use the conversion chart below to find the nominal diameter.

Note: If you measure your outer diameter and it’s more than 12 inches (14 or higher), the nominal diameter is equal to the outer diameter.

To find the inner diameter:

  • Use a ruler or a tape measure to get an accurate inner diameter of your PVC pipe.
  • Use the chart below to convert your measurement into a nominal diameter.

    PVC Pipe Size Chart

    Once you know the inner or outer diameter, you can use this chart to determine the nominal diameter, which is what you’ll need in order to purchase the pipe you need or match your pipe to fittings. Outer diameters for schedule 40 and schedule 80 pipes are the same, but the inner diameters will vary, so be sure you’re consulting the right chart. Regardless of schedule, nominal sizes of pipes will always match nominal sizes of fittings.

    Schedule 40 PVC Pipe Sizes

    Nominal SizeOuter DiameterAverage Inner DiameterMinimum Wall
    1/8".405.249.068
    1/4".540.344.088
    3/8".675.473.091
    1/2".840.602.109
    3/4"1.050.804.113
    1"1.3151.029.133
    1 1/4"1.6601.360.140
    1 1/2"1.9001.590.145
    2"2.3752.047.154
    2 1/2"2.8752.445.203
    3"3.53.042.216
    3 1/2"43.521.226
    4"4.53.998.237
    5"5.5635.016.258
    6"6.6256.031.280
    8"8.6257.942.322
    10"10.7509.976.365
    12"12.75011.889.406
    14"1413.073.437
    16"1614.940.500
    18"1816.809.562
    20"2018.743.593
    24"2422.544.687

    Schedule 80 PVC Pipe Sizes

    Nominal SizeOuter DiameterAverage Inner DiameterMinimum Wall
    1/8.405.195.095
    1/4".540.282.119
    3/8".675.403.126
    1/2".840.526.147
    3/4"1.050.722.154
    1"1.315.936.179
    1 ¼"1.6601.255.191
    1 ½"1.9001.476.200
    2"2.3751.913.218
    2 ½"2.8752.290.276
    3"3.52.864.300
    3 ½"43.326.318
    4"4.53.786.337
    5"5.5634.768.375
    6"6.6255.709.432
    8"8.6257.565.500
    10"10.7509.493.593
    12"12.75011.294.687
    14"1412.410.750
    16"1614.213.843
    18"1816.014.937
    20"2017.8141.031
    24"2421.4181.218

    What’s next?

    When you’ve found the size of the PVC pipe you have, you can get the fittings and pipes you need from Maxx Supply. Maxx Supply supplies a comprehensive range of industrial piping and ducting solutions to businesses and consumers for commercial and DIY projects. If you’re still not sure of what you need, a Maxx Supply associate can help you find the right size and the right equipment for any application.